The investigation of thin soft matter films with neutrons allows a non-destructive probe with good scattering statistics. It is used in a broad field of scientific interest that studies structures and performance of various soft matter systems such as hydrogels or organic solar cells. However, soft matter samples are very sensitive to humidity and temperature and require well-defined ambient...
The water management in polymer electrolyte membrane fuel cells (PEMFCs) has been studied extensively with neutron imaging. In contrast, for anionic electrolyte membrane fuel cells (AEMFCs), which provide a high economic potential based on the fact that no noble metal catalysers need to be employed, very few studies of water management exist to date.
A main limitation of investigating the...
Commercial 18650-type C/LiNi0.33Mn0.33Co0.33O2 lithium-ion cells were exposed to different charging, discharging and resting conditiones to understand their influence on the aging behaviour. When cycled with a standard 1C charging and discharging rate and different resting times, the cells show a nonlinear capacity fade after a few hundred equivalent full cycles. By increasing the discharging...
Positron annihilation is a non-destructive tool for investigating vacancies in materials. A positron annihilates with an electron and emits gamma rays in solids. Their energy distribution is broadened by the momentum component of the annihilating electrons. A positron could be trapped by a vacancy because of Coulomb repulsion from ion cores. Because the momentum distribution of the electrons...
Microgels are macromolecular networks swollen by the solvent they are dissolved in. They are unique systems that are distinctly different from common colloids, such as, e.g., rigid nanoparticles, flexible macromolecules, micelles or vesicles. When swollen, they are soft and have a fuzzy surface with dangling chains and the presence of cross-links provides structural integrity. They find...
Nowadays, lead acid batteries still offer a reliable and cost-effective solution compared to lithium-ion batteries, which can be adapted to different types of energy storage applications. After more than 150 years of use, the energy density of these batteries still presents substantial room for improvement. Our research group is monitoring the processes, which occur inside lead acid batteries...
The synthesis of complex microgel architectures triggers the necessity of structural characterization. Small angle neutron scattering (SANS) is well suited for this purpose. SANS is capable of simultaneously measuring both average particle sizes and polydispersity, as well as the local structure of colloidal gels. SANS and isotopic substitution may reveal the distribution of monomers within...
Poly(N-isopropylacrylamide)(PNIPAM) is a classical representative of stimuli-responsive polymers in various polymer systems like microgels, brushes, micelles [1-2]. Application of external stimuli such as temperature or pressure induces structural alterations of the polymer systems. It makes them the promising candidates for various application. However, the polymer parameters and the...
$A_2Zr_2O_7$ oxides have been studied partially because of their possible use in the storage of nuclear waste (1) or as a photochemical catalyst materials (2). The overall $A_2Zr_2O_7$ structure is cubic (of pyrochlore type for light rare earth, defect-fluorite type for heavy rare earth ones). The pyrochlore zirconates are thoroughly investigated quantum spin ice candidates, whereas heavy rare...
Experimental work and simulations were carried out to determine the angular distributions of neutrons and yields of the 9Be(d, n) reaction overall angular range (360 deg) on a thick beryllium target as an accelerator-based neutron source at incident-deuteron energy 13.6 MeV. The neutron activation method was used in the experimental part using aluminum and iron foils as detectors to calculate...
Probing the internal structure of macroscopic liquid foams, like their film thickness, is very difficult or even impossible with optical methods, since foams strongly scatter light in the visible range. To overcome this problem, small angle neutron scattering (SANS) can be used, as already demonstrated by Axelos et al. [1].
This contribution addresses foams stabilized by Poly-N...
Cold-neutron triple-axis spectrometers (TAS) are focused on the investigation of low-energy excitations within condensed matter physics, covering a broad selection of topics from superconductivity to magnetism. The original design of this type of spectrometer measures an individual point in a large (Q, E) space for each instrument setting. In order to increase the useful signal on TAS,...
With Boron-10 converters replacing helium-3 the total sensitive detector area per instrument increased likewise due to the lower efficiency per layer. However, commonly used alloys for substrates contain a significant amount of radioisotopes which lead to an undesired background counting rate. For detector applications exposed to a low flux, like in our case measuring environmental neutrons...
The chemical fingerprint of a representative corpus of sherds from Central Europe, North Africa, Western and Central Asia was identified by using neutron activation analysis (NAA) at the FRM II. A first batch of 30 homogenized pottery samples from archaeological field projects of LMU researchers were analysed using standard procedures following both short and long-time irradiation and measured...
Archaeological iron finds often undergo a secondary destructive corrosion process after excavation. Since chlorine is supposed to play a major role in this process, it is important to have a method for determining the chlorine content of such objects non-destructively, both for assessing the danger of corrosion and to verify the efficiency of methods trying to remove the chlorine. Neutron...
Co-nonsolvency occurs if a mixture of two good solvents causes the collapse or demixing of polymers into a polymer-rich and a solvent-rich phase in a certain range of compositions of these two solvents. The nonionic thermo-responsive polymer, poly(isopropylmethacrylamide) (PNIPMAM), which features a lower critical solution temperature (LCST) in aqueous solution, has been widely used to...
The combination of high pressure, low temperature and high magnetic fields with neutron scattering is of great interest for the study of a wide range of materials, e.g. quantum phenomena where competing magnetic interactions are tuned by pressure. The basic requirement for such experiments is the availability of suitable pressure devices. The most common type of device for high-pressure...
Compact accelerator-based neutron sources (CANS) have the potential to generate neutron beams for scattering studies comparable to research reactors. Such a source is currently developed at Jülich Centre for Neutron Science (JCNS). It is expected to provide thermal and cold neutrons with high brilliance and is therefore called “High Brilliance Source” (HBS). In this framework, the performance...
Cellulose nanofibrils (CNF) have proven their strengths in conductive and transparent films. A promising route for fabricating porous CNF films on large scale is spray deposition using water-based technologies; the resulting porous CNF templates are excellent candidates to infiltrate conductive polymers for functionalization. We used poly(3,4-ethylenedioxythiophene) polystyrene sulfonate...
Nowadays thermoelectric generators are considered a promising technique for heat waste recovery as they enable a direct conversion of a temperature gradient into electrical power. Nevertheless, so far these devices are made of inorganic semiconducting bulk alloy materials like Bi2Te3, which typically contain rare and toxic elements, and are very difficult and expensive to process. Therefore,...
Prothymosin Alpha (ProTa) is one of the peculiar intrinsically disordered proteins. It is strongly negatively charged and is directly involved in various cellular mechanisms such as chromatin modification. Previous studies on that protein using single molecule techniques revealed structural changes when exposed to a strong denaturant Guanidinium Chloride (GndCl). Additionally, the emergence of...
The diblock copolymer PMMA-b-PNIPAM forms micelles in solution that feature a permanently hydrophobic core and a thermo-responsive shell. While a typical shell collapse transition can be induced via a temperature stimulus at the LCST, the PNIPAM block is also sensitive to the composition of the surrounding solvent. Although water and organic cosolvents individually act as good solvents to the...
Stimuli responsive thin films combine the advantages of polymers in bulk, i.e., their increased stability and of polymer solutions, i.e., their fast response and therefore are attractive for a wide range of applications. Towards future applications, we investigate the not yet well understood phenomenon of cononsolvency. For this we prepared thin films of the thermoresponsive diblock copolymers...
The Covid-19 pandemic is a global challenge with unprecedented individual health, societal and economic impact. Scientific research is needed in many fields in order to find solutions for these new challenges. This conference contribution sheds light on how neutrons can contribute to this endeavor. It especially addresses what research options are available at the MLZ for COVID-19 research. Of...
We report on comprehensive high-resolution linewidth measurements of critical antiferromagnetic fluctuations in Ca$_2$RuO$_4$ (CRO214) performed at the neutron resonance spin-echo spectrometer TRISP at FRM II and the cold triple-axis spectrometer FLEXX at BER II. CRO214 is structurally related to the unconventional superconductor Sr$_2$RuO$_4$ [1] and hosts a complex interplay between magnetic...
The neutron instrumentation at the MLZ, in particular Small Angle Neutron Scattering (SANS), reflectometry and macromolecular crystallography allow to investigate structures in the range from one up to several hundred nm in reciprocal space with high statistical accuracy.
In soft matter and biology the neutron contrast between hydrogen and deuterium is used to gain deep and quantitative...
The European Spallation Source (ESS) is expected to be the world’s most powerful neutron source. Among the endorsed instruments foreseen for day one instrumentation at ESS, is the cold time-of-flight spectrometer CSPEC, collaboration between the Technische Universität München, and the Laboratoire Léon Brillouin. CSPEC will probe the structures, dynamics, and functionality of large hierarchical...
The PERC (Proton and Electron Radiation Channel) facility is currently under construction at the MEPHISTO beamline of the FRM II, Garching. It will serve as an intense and clean source of electrons and protons from neutron beta decay for precision studies. It aims to improve the measurements of the properties of weak interaction by one order of magnitude and to search for new physics via new...
Non-lamellar lipid membranes are highly relevant in lots of biological processes like exo/endocytosis, and cell division; an interesting case is represented by inverse bicontinuous cubic phase membranes. By designing biologically inspired synthetic bicontinuous cubic phase membranes, it is possible to exploit the amphiphilic nature of their lipid components to encapsulate hydrophobic,...
Molecular brushes with thermoresponsive copolymer side chains have attracted attention for drug delivery purposes because of their elongated shape and their versatility. In the present work, two molecular brushes having copolymer side chains composed of poly(propylene oxide) (P) and poly(ethylene oxide) (E) are studied in aqueous solution. The side chains are either a diblock (PbE) or a random...
Modern Multi-Wire-Proportional-Chambers (MWPC) operating with 10B4C films as solid-state-converter can surpass the performance of ones based on 3He in terms of position resolution and count rate capability at similar detection efficiency [1, 2]. The use of large area coated converters on thin foils forces to develop a mechanical concept to avoid deformations of the neutron sensitive surface...
Mushroom is a concept of an indirect neutron spectrometer with its secondary spectrometer based on a super flat-cone analyser made of highly oriented pyrolytic graphite with an array of position-sensitive detectors (PSD) below it. This combination of the analyser and PSD gives the complete information of the outgoing wave vectors from each detected point on the PSDs. The idea has been first...
Superalloys are key materials for energy conversion in jet engines, rockets or power plants. For more than 60 years, Ni-based superalloys are in use. Due to their unique two-phase microstructure, they retain their strength up to 70% of their melting temperature. In 2006, a new, ternary Co3(Al,W) compound was discovered that enabled the development of Co-based superalloys with similar...
Inelastic neutron scattering studies of the spin dynamics of archetypical ferromagnets have been conducted since the invention of those methods. However, the results were limited to relatively large momentum transfers q by experimental difficulties, mainly the coarse resolution of modern TAS or TOF instruments. Utilizing the modern method, a neutron resonance spin echo technique, we...
The structure of concentrated solutions of tetraethyleneglycol dodecyl ether has been compared against a smooth surface and one with a roughness of the order of the lamellar spacing. This has been done in order to investigate the role perturbations have on the overall lamellar order, when these have length scales of the order of the interactions between neighboring lamellae. The results...
We discovered nitrogen/defect ordering leading to elpasolite-type superstructures in inverse perovskites with the general composition (A3Nx)Tt (A = Ca, Sr, Ba; Tt = Si, Ge, Sn, Pb). Due to the large scattering length of nitrogen, neutron powder diffraction is crucial when it comes to illuminating the nature of these superstructures.
For example, high quality powder X-ray diffraction patterns...
The saponin glycyrrhizin is the main sweet-tasting part of the liquorice root and is often used as a sweetener and emulsifier. It is known to interact strongly with cholesterol and has anti-viral activity. Using small, unilamellar lipid vesicle (SUV) as model membrane, we study the mixing properties of glycyrrhizin with the phospholipid 1,2-dimyristoyl-$sn$-glycero-phosphocholine (DMPC) by...
Rechargeable solid-state magnesium batteries are considered for high energy density storage and usage in mobile applications as well as to store energy from intermittent energy sources. Recently, magnesium borohydride, Mg(BH$_4$)$_2$, was found to be an effective precursor for solid-state Mg-ion conductors. The mechanochemical synthesis tends to form amorphous Mg(BH$_4$)$_2$ and it has been...
Although addition of silicon to a conventional pure graphite anode leads to a large increase in energy densities, profound morphological changes associated with it, due to repeated (de-)lithiation, may lead to rapid degradation in cell performance. A reversible (de-)lithiation of Li-ions and the formation of a homogenous SEI layer in the initial cycles is therefore crucial.
In this work, we...
The investigation of protein diffusion is essential for a comprehensive understanding of living cells.
Recently, the volume fraction dependence of the short-time center-of-mass self-diffusion of immunoglobulin (IgG) in naturally crowded environments has been reported. A remarkable agreement between simulations and experiment explained the agreement between the volume fraction dependence of...
In a CANS, different from a research reactor or a spallation source, the primary neutrons are produced inside a volume below 200 cm$^3$. One of the main requirements for a well-optimized research neutron source is to convert this compact fast neutron cloud into a compact thermal neutron cloud. There the geometry needs to be suitable for the extraction of neutron beams towards the instruments....
The TOF diffractometer Epsilon at the beamline 7a of the IBR-2 reactor is dedicated to the high resolution measurements of applied and residual strains of geological samples and functional materials.
A four-axis goniometer permits a rotation around one axis and translation in 3 mutual perpendicular directions. It allows us to measure a strain profile of six independent component of strain...
Neutron scattering experiments involving soft matter materials often require specific contrast to observe different parts of the materials. In order to increase the availability of deuterium labelled materials, we are establishing deuteration support to MLZ users. At this state, we are focusing on a limited number of projects, but in the future, a proposal based deuteration service will be...
Neutron scattering experiments involving soft matter materials often require specific contrast to observe different parts of the materials. In order to increase the availability of deuterium labelled materials, we are establishing deuteration support to MLZ users. At this state, we are focusing on a limited number of projects, but in the future, a proposal based deuteration service will be...
Event-Mode Imaging is a method where the final image is obtained as a summation of individually acquired particle interactions. In fast neutron scintillators, scattering of the high energy neutrons generates recoil protons. Ionization by the protons leads to creation of visible light in the form of a cone. The low spatial resolution in fast neutron imaging results from blurring introduced by...
Studying thermal protein denaturing provides valuable information on structural and dynamic aspects related to protein function. Here, we use small-angle and quasielastic neutron scattering (SANS and QENS) to shed light on the denaturing of bovine serum albumin (BSA) in the presence and absence of NaCl.
SANS reveals the temperature-dependent formation of a crosslinked BSA network. The...
Disordered regions as found in intrinsically disordered proteins (IDP) or during protein folding define response time to stimuli and protein folding times. Neutron Spinecho Spectroscopy is a powerful tool to access directly collective motions of the unfolded chain to observe conformational relaxations. During thermal unfolding of native Ribonuclease A we examine structure and dynamics of the...
Organic semiconductors have attracted intensed attention because of their potential use in mechanically flexible, lightweight, and inexpensive electronic devices. Especially, PEDOT:PSS is the most studied conducting polymer system in thermoelectric devices due to its intrinsically high electrical conductivity, low thermal conductivity, and high mechanical flexibility. The energy conversion...
Being intrinsic to nanomaterials, disorder effects crucially determine the properties of magnetic nanoparticles, such as their heating performance [1-3]. However, despite the great technological relevance and fundamental importance, a quantitative interpretation of the three-dimensional magnetic configuration and the nanoscale distribution of spin disorder within magnetic nanoparticles remains...
The High Brilliance Neutron Source (HBS) project was initiated at the Jülich Centre for Neutron Science of the Forschungszentrum Jülich (JCNS). This project aims to develop an accelerator-driven pulsed neutron source operating at low energy (below the spallation threshold) with high current ion beams (~100 mA) and optimized to deliver high brilliance neutron beams to a variety of neutron...
Following dynamics during kinetically changing samples is a major challenge. With recent developments of analysis frameworks, accessing the short-time self-diffusive properties of protein solutions by measuring specific energy transfers (FWS) via neutron backscattering, kinetically changing samples can be investigated. More detailed information (internal dynamics and immobile fraction of the...
Precision measurements of $\beta-$decay spectra can provide exquisitely sensitive tests of various predictions and underlying symmetry assumptions of the Standard Model (SM) of Particle Physics. Possible symmetry violations can alter the shape of $\beta$-decay spectra in characteristic ways. Beyond SM physics e.g. causes the finite masses of neutrinos that alter the $\beta-$decay spectrum of...
Latest research in the field of hybrid photovoltaics focuses on the benefits of inorganic and organic materials. Flexibility, low cost and large-scale production are the most valuable properties of organic components whereas the inorganic components add chemical and physical stability. So far thin films based on titanium dioxide are well investigated, whereas less is known about...
We present the capabilities of TRISP both for high-resolution spectroscopy and diffraction and show typical experimental examples. TRISP is a thermal three axis spectrometer incorporating the resonant spin-echo technique. Typical applications include the measurement of linewidths of phonons and spin excitations in an energy range 0.5-50meV, and the energy width of quasi-elastic scattering,...
Diffraction with neutrons is one of the most versatile tools for detailed structure analysis on various hot topics related to physics, chemistry and mineralogy. The scd HEiDi at the Heinz Maier-Leibnitz Zentrum (MLZ) offers high flux, high resolution and large q range, low absorption and high sensitivity for light elements by using the Hot Source of FRM II.
At very high temperatures studies...
Recent progress with soft nanostructures will be reviewed. Traditionally, data analysis follows two approaches, roughly depending on your geographic position with respect to the Rhine river. While “inversion” predominates in the east, “modeling” is more western. In short, “inversion” minimizes the use of a-priori knowledge, while modeling starts with an idea of what the structure might be,...
Within the last decade, neutron instrumentation improved in many ways. We are no longer presenting original datasets in consequence of drastic increase in the amount of taken data. Published figures depends on many independent parameters, like binning size, data reduction algorithms, instrumental corrections. It is clear that in order to to keep our data useful we need to change the ways how...
The world of computing always strives for a faster solution. The current work made an effort to make the program sassena faster, which calculates the neutron and x-ray.scattering data from atomic simulations, such as molecular dynamics (MD). This can be achieved using different parallelization strategies, e.g. vectorization, thread-based parallelism and distributed memory parallelism. Current...
The coupling between elementary excitations in condensed matter can give rise to novel functional properties and exotic states, such as superconductivity, multiferroicity, or various types of polar order. We are particularly interested in the CeTAl3 (T is a transition metal), family of compounds, for which an unusual bound state was reported in CeCuAl3 and CeAuAl3. It arises due to the...
Metal halide perovskites are remarkable optoelectronic materials, within a decade the photovoltaic (PV) power-conversion efficiencies have risen from a few percent to exceed 25%. Yet advance toward the theoretical Shockley-Queisser limit value has slowed and this has been attributed to defect-assisted nonradiative recombination. First-principles calculations provide detailed insight on point...
Fast neutron imaging is a technique to investigate large objects where X-rays or thermal neutrons face limitations due to their comparatively low penetration capabilities. Compared to thermal neutrons, where thin scintillators (< 100um) generally provide good detection efficiencies (>> 1%) at high spatial resolutions in the 10th of microns range, fast neutrons currently require mm-thick...
Magnetic anisotropy does not only play a vital role in the formation and stability of long-range magnetic orders but also affects the ability to manipulate such spin structures. Via case studies, I show how competition of single-ion anisotropies at different magnetic sites can lead to unconventional magnetic orders and how modulation vectors of magnetic spirals can be controlled by tuning anisotropy.
Organic ligands are commonly employed to stabilize nanoparticle sizes, shapes and long-term colloidal stability in dispersions. For Cadmium chalcogenides, ethylenediaminetetraacetate (EDTA) seems a good candidate due to its strong chelating action towards Cd2+. Further, EDTA-capped CdS nanoparticles were proven to be stable in aqueous dispersion at room temperature over months.[1,2]
Without...
Due to the high theoretical capacity (3860 mAh g-1) and the lowest discharge/charge potential (-3.04 V vs. standard hydrogen electrode) of the lithium metal anode, rechargeable lithium metal batteries have been identified as one of the most advanced energy storage systems, which hold great promise for practical applications. However, lithium metal batteries suffer from serious safety concerns...
What is well established at many synchrotron beam lines is still in the development phase at neutron instruments: in situ light scattering techniques for on-beam sample control. Biological samples often show a sufficiently broad spectral range where light absorption does not play a dominant role. This enables in situ sample control using dynamic and static light scattering techniques. Many...
Intermetallic TiAl alloys represent a novel class of lightweight high temperature materials for applications in aero and automobile industries. One of their most impressive example of use is replacing the twice as dense Ni-based turbine blades in the last stages of the aero engine in the Airbus A320neo family, yielding to a decrease of noise and CO2 emission.
Nevertheless, there is need for...
Material research in all its complexity continuously calls for new analysis solutions to solve sophisticated issues in one go.
Rheology deals with the flow and deformation of matter. Applying shear force to a material can result in orientation or crystallization. With small-angle X-ray scattering (SAXS) structural parameters of nanomaterials such as size, shape, inner structure, and...
Organic solar cells (OSCs) have underwent significant improvements via both, novel organic synthesis and easy fabrication methods. However, the peeling-off of the top electrode fabricated by thermal evaporation (TA) leads to an intrinsic device degradation, which is one of the main reasons for the performance losses of OSCs. TA has the drawback of establishing only a soft contact between the...
Cell membranes play a fundamental role in protecting the cell from its surroundings, in addition to hosting many proteins with fundamental biological tasks. Drugs are able to perturb the structure of cell membranes, which can ultimately give rise to undesirable effects. Thus, a study of drug/lipid interactions is a necessary and important step in fully clarifying the role and action mechanism...
Phospholipid membranes are the construction material of cell membranes and solutions of phospholipid vesicles find a range of applications in technical, medical and biological applications.
We previously showed the structure (neutron reflectometry, GISANS) and the dynamic behavior (GINSES) of L-α-phosphatidylcholine (SoyPC) phospholipid membranes. [1,2] We established a multi-lamellar...
Laser Powder Bed Fusion (L-PBF) is an additive manufacturing technique enabling the design of complex geometries that are unrivalled by conventional production technologies. Nevertheless, L-PBF process is known to induce a high amount of residual stresses (RS) due to the high temperature gradients present during powder melting by laser. High tensile residual stresses are to be found the edges...
The interaction of engineered nanomaterials with living systems is mediated by biological barriers, determining their biological fate and cytotoxicity. Understanding the interaction of nanoparticles (NPs) with biological interfaces is the key to fill the gap between NPs development and end-use application. Lipid-based synthetic membranes can be used to mimic natural interfaces under simplified...
Layered LiNixCoyMn1-x-yO2 (NCM) oxides with core-shell morphology have been found to be prospective cathode candidates for advanced lithium-ion batteries. The electrochemical performances of NCM cathodes are tied to the transition metal relative ratios, thereby it is difficult to determine the real structure of core-shell NCM materials and to understand the synergistic effect of core and shell...
Compact accelerator-based neutron sources (CANS) produce neutrons by low energy nuclear reactions well below the spallation threshold making them a cost-efficient and effective alternative to spallation and reactor based neutron sources. Such low energy (p, n)-reactions produce less and lower energy byproducts thus reducing significantly the radiation level. This allows the construction of a...
Hole doping in Nd2NiO4.00 can be either achieved by substituting the trivalent Nd atoms by bivalent alkaline earth metals or by oxygen doping, yielding Nd2NiO4+δ. While the alkaline earth metal atoms are statistically distributed on the A-cation sites, the extra oxygen atoms in interstitial lattice remain mobile down to ambient temperature and allow complex ordering scenarios depending on δ...
The Cs2CuCl4-xBrx mixed system exists in orthorhombic and tetragonal polymorphs and is an example of the low-dimensional quantum spin systems. The different Cu2+ environments and their influence on the magnetic properties are important to understand the change of magnetic behaviour by applying magnetic field. The orthorhombic mixed system was studied by neutron single crystal diffraction with...
Novel block copolymers consisting of two anionic polyelectrolyte blocks [NaPA and NaPSS] have been synthesized. In the presence of certain amounts of divalent cations such as Calcium, Strontium and Barium, supramolecular structures are formed. The overall size and molecular weight of these structures have been obtained by combined static and dynamic light scattering (SLS & DLS). Via...
Stimuli-responsive polymers in aqueous solution form mesoglobules in the two-phase region of the temperature-pressure phase diagram. While the formation of mesoglobules has been amply studied [1], their dissolution and associated structural changes are hardly explored. To elucidate the kinetics of chain swelling and mesoglobule disintegration in a semi-dilute aqueous solution of the...
KOMPASS is a polarized cold-neutron three axes spectrometer (TAS) currently undergoing its final construction phase at the MLZ in Garching. The instrument is designed to exclusively work with polarized neutrons and optimized for zero-field spherical neutron polarization analysis for measuring all elements of the polarization matrix. In contrast to other TASs, KOMPASS is equipped with a unique...
The KWS-1 small-angle neutron scattering instrument is operated by JCNS at MLZ [1]. The instrument covers a q-range from 0.0007 to 0.5 Å⁻¹ with a selectable wavelength span from 4.7 to 20 Å. The maximum neutron flux on the sample is 1×10⁸ cm⁻² s⁻¹, making it one of the most intense SANS instruments in the world.
The instrument is equipped with transmission supermirror polarizer, adiabatic...
KWS-2 is a classical SANS diffractometer using a combination of pinholes with different neutron-wavelengths and detector distances as well as a focusing mode with MGF2 lenses to reach a large q-range between 0.0002 and 0.5 1/Å. A wide-angle detection option is currently planned to allow for measurements up to 2 1/Å, by combining SANS and WANS methods.
The instrument is designed for high...
Phase-change materials can be rapidly and reversibly switched between the amorphous and crystalline states in a few nanoseconds. They have been successfully employed for non-volatile phase-change memory applications. However, the dynamics of atomic rearrangement processes and their temperature dependence, which govern their ultrafast switching, are not fully understood. Here, using...
Commercial Lithium-Ion Battery (LIB) cells are mostly based on graphite as anode material. During the first inter¬calation of Li into graphite, the electrolyte gets reduced at the anode, forming a nm-thick surface layer, the so-called solid electrolyte interphase (SEI). The SEI stops further electrolyte reduction but consumes Li during its formation. Neutron depth profiling (NDP) is a...
Anisotropic low-temperature properties of the cubic helimagnet ZnCr2Se4 in the single-domain spin-spiral state are investigated by a combination of neutron scattering, thermal conductivity,and dilatometry measurements. In an applied magnetic field, neutron spectroscopy shows a complex and nonmonotonic evolution of the spin-wave spectrum across the quantum-critical point...
The development of composite materials based on graphene, included in polymer matrices of different nature, and the study of the relationship between their structure and properties using complementary methods of research are due to several reasons. First is the search for new magnetic materials promising in spin electronics. Second, there is interest in physical processes in highly defective...
Magnetic materials containing octahedrally coordinated Ir$^{4+}$ ions can give rise novel J$_{eff}$ =$\frac{1}{2}$ magnetic moments due to the interplay of strong spin-orbit coupling, onsite Coulomb repulsion and crystalline electric field. The exchange interaction between such moments depends on the geometry of the exchange paths between the magnetic ions and could be **highly...
The antiferromagnetic compound Mn5Si3 is an interesting material for applications since it is hosting rich physics, such as the inverse magnetocaloric effect [1] and a large anomalous Hall effect [2]. Despite the intense research activity over the past decades [1-5], many open questions remain regarding the minimal magnetic model Hamiltonian, the role of the spin fluctuations in the...
The high-intensity reflectometer MARIA of JCNS is installed in the neutron guide hall of the FRM II reactor and is using a velocity selector (4.5Å<λ¬<40Å) as a primary wavelength filter with 10% resolution. In combination with a Fermi-Chopper the wavelength resolution can be increased to 1% or 3%. The beam is optionally polarized by a double-reflecting super mirror and the elliptically...
A major component of the saltatory nerve signal conduction is the multilamellar myelin membrane around axons. In demyelinating diseases like multiple sclerosis, this membrane is damaged which leads to severe problems in nerve conduction. In literature different values for the lipid composition of healthy myelin sheath and myelin in the condition of experimental autoimmune encephalomyelitis -...
The RESEDA (Resonant Spin-Echo for Diverse Applications) instrument has been optimized for the measurement of quasi-elastic and inelastic processes over a wide parameter range. One spectrometer arm of RESEDA is configured for the MIEZE (Modulation of Intensity with Zero Effort) technique where two precisely tuned radio-frequency (RF) flippers prepare the neutron beam such that it yields a...
Previous studies found non-monotonous lattice strain evolutions at small plastic deformations in the Nickel-based superalloys Inconel 718 and Haynes 282. For studying the micromechanical causes of this behaviour, the dependence of these effects on dislocation density, deformation history, and temperature history was examined. Due to the material‘s more readily observable non-monotonous lattice...
It is evident from several analyses performed on steel samples that the production of arms and armor used cutting edge technology of that time so a study of such artefacts can give fundamental details about the technological skills of a specific area or period. In order to correlate similar samples of a specific age or provenance, it is important to build trustworthy classification parameters....
One aspect for the development of non-conventional solar cells should be the sustainability of the production process of devices. Following this idea, we developed hybrid solar cells, which can be processed out of aqueous solution. The active layer of these devices is based on laser-processed titania nanoparticles dispersed in a water-soluble polythiophene. The active layers were produced with...
Over the last decades, the focus of research has been shifted towards the field of organic electronics due to their advantageous properties, such as low-cost manufacturing processes, versatility, flexibility, as well as their tunable characteristics, such as absorption and solubility. These properties open up a wide range of applications, especially, in the field of photovoltaics. Hence,...
Located at the SR10 at the FRM II, NECTAR is a versatile instrument and designed for the non-destructive inspection of various objects by means of fission neutron radiography and tomography. Compared to the Z-dependency of X-ray and gamma imaging, fission neutrons have the strong advantage of often providing similar contrast for heavy and light materials. Only few facilities around the world...
NECTAR is a unique beam-line with access to fission neutrons for non-destructive inspection of large and dense objects, where thermal neutrons or X-rays face limitations due to their comparatively low penetration. With the production of fission neutrons at the instrument, as well as neutrons interacting with beamline geometry, such as the collimator, gamma rays are inevitably produced in the...
The polymeric materials used in fuel cells applications either as proton (PEMFC) or anion (AEMFC) exchange membranes are characterized by a nanoscale phase separation into hydrophilic domains and hydrophobic crystalline regions, which enables a high conductivity and provides a good chemical and mechanical stability of the membrane. Owing to its high proton conductivity and chemical stability,...
Pharmaceutical drug formulations for oral delivery depict after patient intake a stepwise structure development of disintegration to micro-particles, dissolution of drug nano-complexes, interaction with bile and lipids and uptake by the intestinal membrane proteins (receptors). The processes are critical for therapy and applicability of drug and formulation, especially with hydrophobic or...
Pharmaceutical drug formulations for oral delivery depict after patient intake a stepwise structure development of disintegration to micro-particles, dissolution of drug nano-complexes, interaction with bile and lipids and uptake by the intestinal membrane proteins (receptors). The processes are critical for therapy and applicability of drug and formulation, especially with hydrophobic or...
Cellulose nanofibrils (CNF) as a sustainable biomaterial are excellent building blocks for mechanically exceptional materials and functional coatings. Yet, the water uptake and response to humidity still poses a challenge. We first demonstrate a facile route to prepare large-scale cellulose-based nanostructured thin films with a low surface roughness down to 2.5 nm on (20 × 100) mm$^2$...
The work hardening and softening behaviour of SiCp/Mg-5Zn composites influenced by PDZ (particle deformation zone) size were analysed and discussed using neutron diffraction experiment under in-situ tensile deformation at STRESS-SPEC. Peak broadening evolution was interpreted as the modification of dislocation density, which discovered the effect of dislocation on the work hardening behaviour...
The MLZ makes extensive use of modern neutron guides to transport and distribute the neutrons over large distances, which are installed and maintained by the neutron optics group. Adapted to the needs of the instruments with respect to wavelength distribution and angular dispersion the guide elements are coated by 58Ni or Ni/Ti supermirror coatings with m values up to 3.5 either procured...
Neutron instruments are key to productive and successful experiments. Their continued development and the implementation of new ideas is the basis for enabling excellent science, increase performance of instruments or to open new fields. I will give a brief cross section of ongoing instrument developments in the Endurance program at the Institut Laue-Langevin (ILL).
In particular, recent and...
Recently, the discovery of superconductivity in the Sr-doped nickelates RNiO$_2$ (R = Pr, Nd) has attracted widespread attention. The synthesis of the RNiO2 compounds has been achieved by topotactic reduction of the non-superconducting perovskite phase RNiO$_3$, removing oxygen from the crystal lattice in a controlled fashion. Remarkably, new electronic and magnetic phases can also occur in...
Interfaces between iron oxide nanoparticles (IONP) and water are of great importance in various fields spanning biomedicine, waste water treatment and catalysis. Recently, we could distinguish adsorbed water species and extended hydration layers around IONPs via a double-difference X-ray pair distribution function (dd-PDF) analysis.1 Details of the interfacial hydrogen bond network shall now...
Recent developments in the instrument design of neutron backscattering spectrometers allow to measure the total scattering function $S(q,\omega)$ with quasi-continous energy transfers but also with specific energy transfers - so called elastic fixed window scans (E/IFWS)- with a high energy resolution. While several models have been developed for the analysis of EFWS [1], there are only few...
The polarized single-crystal diffractometer POLI offers two types of polarized neutron diffraction experiments: spherical neutron polarimetry (SNP), also known as full three-dimensional polarization analysis in zero magnetic field, and classical polarized neutron diffraction, also called flipping-ratio (FR) method, in high applied magnetic fields. Recently, the available sample environment of...
NICOS is the standard user interface for the instrument control at the MLZ instruments. Because of the success and the user acceptance the ESS made the decision to used it as well for their instrument control. The SINQ at the PSI was also looking for a new instrument control software and found NICOS.
The webinar is splitted into two sections, a presentation about NICOS with the following...
The high resolution neutron/ X-ray contrast reflectometer NREX, operated by the Max Planck Institute for Solid State Research, is designed for the determination of structural and magnetic properties of surfaces, interfaces, and thin film systems.
The instrument is an angle-dispersive fixed-wavelength machine with a default wavelength of 4.28 Å. A horizontal focusing monochromator gives the...
The determination of residual stresses becomes more complicated with increasing complexity of the structures investigated. Unlike most of the fabrication techniques, laser powder bed fusion allows the production of lattice structures without any additional manufacturing step. These lattice structures consist of thin struts and are thus susceptible to internal stress-induced deformation. In the...
Processes leading up to nucleation are pedantically known to proceed via the emergence of a low-amplitude, long wavelength instability through the material, creating the disturbances for a nucleation process to transpire. Owing to the thermodynamic instability of the high surface energy nanostructures, the nuclei concatenate to form higher surface area intermediates. The processes spanning...
Neutrons can be produced by fission in nuclear reactors, spallation using high-power proton accelerators, and nuclear capture reactions with low-energy proton accelerators. While the first two techniques are used very successfully in Europe, the later option only recently gained greater interest. Using high current low energy proton beams bombarding a metal target a neutron flux comparable...
Specific target Nanoparticles for therapy of cancer and other diseases were assembled from lipids, polymers, and pharmaceutical drugs or mRNA. For cell targeting proteins were bound to the surface (corona). The structure in solution is analyzed by dynamic light scattering DLS combined with neutron small angle scattering SANS, SAXS, metal specific X-ray scattering...
High entropy alloys (HEAs), which comprise more than five principal elements, are presently of great interest in materials science and engineering. A predication by CALPHAD has been performed in a new AlTiNbVW HEA, which shows that this alloy consists of two similar bcc phases in the as-cast condition. Current work is to study the phase composition in this multicomponent alloy system at...
Thermo-responsive polymers show a strong change in volume towards slight changes of their surrounding temperature. While this behavior is well understood for polymers in solution, less is known about the underlying mechanisms in thin film geometry. In our work, we investigate the phase transition kinetics upon increasing temperature in a thermo-responsive block copolymer thin film, that shows...
Electron-phonon coupling, i.e., the scattering of lattice vibrations by electrons and vice versa, is a common phenomenon in solids and can lead to emergent ground states such as superconductivity and charge-density wave order. Signatures of strong electron-phonon coupling, e.g. softening and broadening of phonons on cooling, are typically assigned to the presence of nested parts of the Fermi...
LaCoO3 features two broad crossovers observed around $T_1 = 100 \,\rm{K}$ and $T_2 = 200 \,\rm{K}$. These crossovers are typically associated with the temperature dependent population of excited spin states of the Co$^{3+}$ ion, which evolves upon heating from the low-spin (LS), $S = 0$, to high-spin (HS), $S = 2$, configuration. Since the CoO$_6$ octahedra expands around the larger HS sites,...
The diblock copolymer PMMA-b-PNIPAM forms micelles in solution that feature a permanently hydrophobic core and a thermo-responsive shell. While a typical shell collapse transition can be induced via a temperature stimulus at the LCST, the PNIPAM block is also sensitive to the composition of the surrounding solvent. Although water and organic cosolvents individually act as good solvents to the...
Thermal density fluctuations of supercritical (SC) CO2 were explored using small-angle neutron scattering (SANS) whose amplitude (susceptibility) and correlation length show the expected maximum at the Widom line. The susceptibility is in excellent agreement with the evaluated values on basis of mass density measurements. A surprising observation is droplet formation above the gas-liquid line...
In the pretreatment of wood it is essential to apply mild conditions for extracting oligomeric cellulose and possibly lignin that can be used for a variety of environmentally friendly products such as polymers. For this, ionic liquids are ideal due to their mixture of polar and non-polar character, which makes them swelling the wood until it bursts to a rather fluffy material. Using small...
Drug-loaded polymer micelles or nanoparticles are being continuously explored in the fields of drug delivery and nanomedicine. Commonly, a simple core−shell structure is assumed, in which the core incorporates the drug and the corona provides steric shielding, colloidal stability, and prevents protein adsorption. Recently, the interactions of the dissolved drug with the micellar corona have...
Macromolecular crowding, i.e. the presence of macromolecules at high volume fractions, affects reaction rates and transport processes in the cell. For reliable quantitative models of cellular pathways, the mobility of individual proteins is thus a key information. Often, the protein mobility is modeled by the self-diffusion of colloidal systems. The underlying assumption that neither the shape...
We report neutron-scattering and ac magnetic susceptibility measurements of the two-dimensional spin-1/2 frustrated magnet BaCdVO(PO4)2. At temperatures well below TN≈1K, we show that only 34% of the spin moment orders in an up-up-down-down stripe structure. Dominant magnetic diffuse scattering and comparison to published muon−spin−rotation measurements indicates that the remaining 66% is...
Quantum disordered states in frustrated magnets are model cases of quantum entanglement and potential hosts for unconventional, fractionalized excitations. The formation of these states is typically associated with competing exchange couplings, although structural disorder can lead to a somewhat similar phenomenology, including the absence of long-range magnetic order and the presence of...
REFSANS is the horizontal ToF reflectometer at the MLZ in Garching. It is designed to carry out specular and off-specular reflectivity, as well as GISANS studies of solid/liquid, solid/air and liquid/air interfaces. Through ToF analysis, REFSANS gives simultaneous access to a range of Q values (with Qmax/Qmin up to ≈ 7), useful to study air-liquid interfaces and kinetic phenomena.
A...
MGML (Materials Growth & Measurement Laboratory) in Prague is an open research infrastructure providing access to the instrument suite dedicated to measurements of a rich spectrum of physical properties of materials in a wide range of temperatures, magnetic and electrical fields, and hydrostatic uniaxial pressures. Together there are 18 furnaces, 3 diffractometers, 5 room temperature...
Heteroanionic hydrides are an emerging class of compounds with representatives showing ionic conductivity [1] or catalytic activity [2]. For holmium hydride oxide HoHO, the disordered CaF2 type structure was assigned and confirmed by powder neutron diffraction [2]. However, the analysis showed a deviation from the 1:1:1 composition: REH2+xO1-x. This demands the occupation of either octahedral...
On-board hydrogen storage is still a challenge for fuel cell vehicles and other mobile applications. Complex hydrides, which contain ions such as BH4- and NH2-, have a high hydrogen capacity in combination with a low weight of the storage material. For example, Li4BH4(NH2)3 contains 11.1 wt.% hydrogen and desorbs more than 10 wt% at 573-673 K. In previous studies the high desorption...
We report on the newest development of sample environment at MLZ
Concentrated solid solution alloys (CSA) with no principle alloying element but a single randomly populated crystal structure exhibit attractive material properties, e.g., high ductility at low temperatures or high irradiation resistance. To understand such phenomena in these alloys, often also named high-entropy alloys, assessment of atomic transport including formation and migration of...
Salt-induced charges in aqueous suspensions of proteins can give rise to complex phase diagrams including homogeneous solutions, large aggregates, and reentrant dissolution regimes. Moreover, depending on the temperature, a liquid-liquid phase separation may occur within the aggregation regime. Here, we systematically explore the phase diagram of the globular protein BSA via its dynamics as a...
The antisymmetric Dzyaloshinskii-Moriya interaction (DMI) plays a decisive role for the stabilization and control of chirality of skyrmion textures in various magnetic systems exhibiting a noncentrosymmetric crystal structure. A less studied aspect of the DMI is that this interaction is believed to be operative in the vicinity of lattice imperfections in crystalline magnetic materials, due to...
Multiferroic materials attract much interest during the last decades as the coupling of electric and magnetic ordering offers an application potential for future memory devices or new type of sensors. The most prominent mechanism for multiferroicity is given by the inverse Dzyaloshinskii-Moriya interaction, where a spiral magnetic structure induces a shift of non-magnetic ligand ions and hence...
The Small-K Advanced DIffractometer (SKADI) is a joint in-kind project of French and German partners to deliver a SANS instrument to the ESS. [1] This contribution will detail the current construction status of SKADI. In addition, further practical requirements on components such as the sample area will be considered. SKADI is designed to deliver
- Flexibility (sample area is approx. 3x3...
Spray deposition is employed to fabricate anisotropic ferromagnetic thin films composed of the ultrahigh molecular weight diblock copolymer (DBC) polystyrene-block-poly(methyl methacrylate) and strontium hexaferrite nanoplates functionalized with hydrophilic groups. During spray deposition, the kinetics of structure evolution of the hybrid films is monitored in situ with grazing incidence...
Stimuli-responsive block copolymers self-assemble in aqueous solution and respond to changes of their environment, rendering them useful as smart nanocarriers for drug delivery and gene therapy. In the present project, we investigate responsive micelles formed by PDMAEMA-b-PLMA or PDMAEMA-b-PLMA-b-POEGMA [1,2]. PDMAEMA is a weak cationic polyelectrolyte and responsive to pH,...
Wormlike micelles exhibit a unique viscoelastic behavior, which has been investigated intensely in the past decades, experimentally as well as by theoretical calculations [1,2]. Within our studies we explore the self-assembled structure and the flow behavior of wormlike micelles formed by mixing a short-chained C${}_8$ cationic surfactant and the sodium salts of omega-9 fatty acids [3]. Within...
Photovoltaics, the direct conversion from sunlight into electricity, has developed into a mature technology during recent past.
Quaternary chalcogenide semiconductors have received increasing attention as absorber material in thin film solar cells, because their constituents are abundant and non toxic. Best performing devices are obtained with off-stoichiometric kesterite-type...
Stimuli-responsive polymers are of interest for applications in drug delivery or tissue engineering. Telechelic block copolymers, where a pH-responsive midblock is end-capped by thermo-responsive end blocks, have great potential due to their ability to form highly tunable micelles or hydrogels.
In the present work, micelles formed by the telechelic pentablock quaterpolymer...
Fluids play a main role in determining the final structural and transport properties in several solvated systems like hydraulic binders[1], hydrogels[2], organogels[3] and colloids in general. Thanks to their peculiar neutron-sample interaction, neutrons are the elective probe to study many hydrogen-rich systems. For this reason, neutron scattering techniques are unique in defining porous...
Polymer chains, grafted to a substrate by one end are usually referred to as polymer brushes (PBs). They are extensively used as thin surface coatings, enabling a tuneable film thickness, as well as high chemical and mechanical stability. Further, a high versatility arises due to the various monomers that can be utilized what may cause sensitivity to external stimuli, e.g. temperature or ionic...
The early transition metals Zirconium and Titanium show very similar chemical and structural properties. The binary Zr-Ti alloys compose a completely miscible system, which is also a boundary system for many bulk metallic glasses (BMGs) and stable quasicrystals. However, the detailed formation mechanisms of these special structures remain largely unknown and are often speculative, since for...
Laser structured electrodes for Li-ion batteries have been reported as a promising approach for improvement of battery performance. The contact area between the electrolyte and active material in the electrode can be modified as a result of the three-dimensional structured electrode surface. The effective Li-ion diffusion pathways are shortened during the charging and discharging of the cell....
In organic photovoltaics, donor - acceptor bulk heterojunctions are often used as active layer due to their superior performance compared to e.g. planar structured devices. In this optically active polymer layer, a photon is absorbed and an exciton created. After diffusion to a donor-acceptor interface, the exciton is dissipated and charge carriers can be extracted at the electrodes.
A...
T-odd effects in the fission of heavy nuclei have been extensively studied during more than a decade in order to study the dynamics of the process. A collaboration of Russian and European institutes discovered the effects in the ternary fission in a series of experiments performed at the ILL reactor [1-2] and the effects were carefully measured for a number of fissioning nuclei. The analogous...
A low-temperature, long-lived (LTLL) electron-positron pair plasma has never been produced in a laboratory environment. The APEX project aims to do so by accumulating positrons from the NEPOMUC beam at MLZ and inject them into a magnetic trap formed with a levitated coil in order to study the unique plasma behavior pair plasmas are expected to exhibit. We present technical design plans for...
Compared to the widely-investigated poly(N-isopropylacrylamide) (PNIPAM), poly(N-isopropylmethacrylamide) (PNIPMAM) has a higher phase transition temperature (43 °C instead of 32 °C). PNIPMAM has a similar chemical structure as PNIPAM, but the additional methyl groups on its backbone may lead to steric hindrance and weaker intramolecular interactions. To understand how these effects affect the...
Particle Physics with neutrons addresses a number of basic and often unique questions of particle physics and cosmology at very low energies. Within the Standard Model of particle physics, neutron beta decay data serves as important input e.g. to investigate the cosmological abundance of light elements and the energy production in the Sun. Searching for new physics, precision measurements...
Polarized neutron diffraction (PND) is a powerful method which provides direct access to the scattering contribution from nuclear-magnetic interference and thus reveals the phase difference between the nuclear and magnetic structure. This technique can be utilized to gain a detailed insight in the microscopic spin ordering at the unit cell level even for complex magnetic structures. Since...
Doppler-broadening spectroscopy (DBS) of the $511 \textrm{keV}$ gamma line generated by positron-electron annihilation provides information on lattice defects. It is sensitive to concentrations as low as 1e-7 vacancies per atom. In addition, the chemical surroundings of defects can be analyzed by coincidence DBS (CDBS). The current status and recent improvements of the CDB-Spectrometer at the...
The neutron backscattering spectrometer SPHERES (SPectrometer for High Energy RESolution) at MLZ is a third generation backscattering spectrometer with focusing optics and phase-space transform (PST) chopper. It covers a dynamic range of ± 31μeV with a high resolution of about 0.66μeV and a good signal-to-noise ratio. The instrument performance has been improved over the recent years by...
Up-regulation of carbonic anhydrase IX (CA IX) expression is an indicator of cancer metastasis and is associated with poor cancer patient prognosis. As such, CA IX has emerged as an attractive cancer target for diagnosis, cancer staging, imaging, and also treatment. However, due to the high level of sequence conservation between human variants of the enzyme, development of isoform-specific...
It has been shown that Total Reflection High-Energy Positron Diffraction (TRHEPD) is an ideal technique to precisely determine the crystalline structure of the topmost and immediate subsurface layers. Novel materials such as topological insulators or 2D materials can be investigated to determine not only the surface structure, but also the substrate spacing and potential buckling.
We...
Dynamics of different folding intermediates and denatured states might have implications in understanding protein folding. Apomyoglobin (apoMb) has been investigated using neutron spin-echo spectroscopy (NSE) and SANS [1] and quasielastic neutron scattering (QENS) [2,3] in different states: native-like, partially folded and completely unfolded. Mean square displacements obtained by QENS showed...
Noncentrosymmetric (NCS) materials present an interesting environment for superconductivity, as parity is no longer a conserved quantity, leading to the possibility of superconducting systems with a superposition of s-wave and p-wave states. Such systems are predicted to have unusual properties, such as large Pauli limiting fields and ‘helical’ vortex states. The dependence of the superfluid...
New high-flux and high-brilliance neutron sources demand a higher count-rate capability in neutron detectors. In order to achieve that goal, the Solid-State Neutron Detector (SoNDe) project developed a scintillation-based neutron detector. It is capable of fully exploiting the available flux current and coming neutron facilities, such as the European Spallation Source (ESS). [1] In addition to...
In this talk, we will present our recent advances in applying magnetic small-angle neutron scattering (SANS) for the in-depth characterization of magnetic nanoparticles.
In the first part, we will discuss the benefits of a Bayesian analysis as the new standard for fitting magnetic SANS data of nanoparticle samples [1]. Such a standardized protocol for the refinement of magnetic SANS data is...
The power conversion efficiency (PCE) of perovskite solar cells (PSCs) reached the champion value of 25.2 %, making this technique competitive with commercial silicon solar cells. Despite such advantages, the application of PSCs is currently limited by combining high performance and operational stability, because PCE of PSCs can degrade due to the presence of temperature, light, humidity, and...
Thermoresponsive double hydrophilic block copolymers exhibit great interest as model scaffolds for pharmaceutical applications due to their controlled potential in drug encapsulation and release. A thorough elucidation of the nanostructure of the formed self-assemblies and its evolution at different temperatures is mandatory to provide tailored design guidelines in targeted therapeutics. We...
Molecular Beam Epitaxy (MBE) is a versatile tool to fabricate high quality and high purity epitaxial thin films. At MLZ, the Jülich Centre for Neutron Science (JCNS) runs an MBE system to provide samples for users who either do not have the expertise to prepare thin film samples for their neutron experiments and/or the equipment.
In other words: If you need thin film samples for your...
The goal of Specular Neutron and X-ray Reflectometry is to infer materials Scattering Length Density (SLD) profiles from experimental reflectivity curves. This talk will focus on describing an original approach to the ill-posed non-invertible problem which involves the use of Artificial Neural Networks (ANN). In particular, the numerical experiments to be described deal with large data sets of...
Reliable mechanical materials data are required for predicting the strain and stress state evolution during assembly, thermal cycling and powering of superconducting magnets. The ingredients for thermomechanical modelling of linear elastic and isotropic magnet materials behaviour are often available. However, taking into account anisotropic mechanical properties, the yielding and flowing of...
The MLZ directors will give an update about the MLZ during 2020 and the plans for 2021.
URANOS (Ultra RApid Neutron-Only Simulation) is a newly developed 3D neutron transport Monte Carlo from thermal to fast energy domains. Emerging from a problem solver for the CASCADE detector development in collaboration with environmental physics the project aims towards providing a fast computational workflow and an intuitive graphical user interface (GUI) for small to medium sized projects....
In order to provide a basic platform for training and first contact research in the field of neutron science, very low flux facilities represent a sufficient starting point. The training and research reactor (AKR-2) with a maximum continuous power of two Watts can be categorized as such a facility. In the course of the last two years, the experimental field of the AKR-2 has been extended...
In the intermediate mixed state (IMS) in superconducting niobium, the mixed attractive/repulsive vortex interaction leads to the clustering of vortices into domains. Not fitting into the conventional type-I and type-II categories, this regime is denoted intertype superconductivity [1].
Using a combination of neutron techniques, we have studied the hierarchical properties of the IMS in bulk...
In aqueous solutions of the thermoresponsive polymer poly(N-isopropylacrylamide) (PNIPAM), the interaction between water and the polymer changes strongly at the demixing transition. Cooperative dehydration causes the polymer chains to collapse and aggregate. Recent quasi-elastic neutron scattering experiments have shown that the susceptibility spectra of hydration water occur at lower...
This presentation will review the work of the MLZ User Committee by describing how it has been working. A short survey of the major points that have been raised will be also be presented. The major purpose of the talk will be to introduce discussions as to what users of MLZ want, and how these objectives can be helped by actions from the User Committee and MLZ.
