The MEPHISTO experimental area is prepared for hosting the new PERC experiment. The actual status of the experimental area will be reported. There will also be an outlook for the technical infrastructure which is in advanced planning status.
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,...
Beside state of the art neutron scattering instrumentation, sample environment is an important pillar to attract the user community. For the efficient use of neutrons, close collaboration between users, instrument scientists and sample environment team is particularly important in order to run experiments smoothly or to provide sample environment for current and future requirements. Some new...
We will present our newest developments in sample environment equipment together with our freshly bought racing horses. This will cover magnets, cryostats, fluids and humidity.
We present our state of the art neutron guide production and other service for the instruments. This comprises also the usage of ³He filter cells for neutron polarisation.
TOFTOF is a direct geometry disc-chopper timeof-
flight spectrometer located in the Neutron Guide
Hall West. It is suitable for both inelastic and quasielastic
neutron scattering and the scientific questions
addressed range from the dynamics in disordered
materials in hard and soft condensed matter
systems (such as polymer melts, glasses, molecular
liquids, or liquid metal alloys), properties...
In addition to the “normal three axes” mode, PUMA is equipped with the multi-analyzer and -detector setup consisting of 11 arbitrarily configurable analyzer-detector channels suited for kinetic experiments to realize an entire momentum and energy scan in a single shot. Moreover, the same setup can be used also for neutron polarization experiments to determine the spin flip and the non-spin...
Reaching minimodule efficiencies of around 17% in 2018 and 15% on ultrathin flexible substrates, commerzialisation of thin-film organic-inorganic metal halide perovskite based solar cells (PSCs) is very promising as next generation solar cells. However, further improvement on upscaling is needed to push for commercializiation. In principle, industrial requirements for fabrication can be met by...
Colloidal quantum dots (QDs) are considered as a promising candidate for being used in next-generation solution-processed thin-film optoelectronic applications. The presently investigated QD thin films are mainly fabricated by a spin-coating, which is a lab-scaled (small-scaled) deposition method and the insights from the structure related aspects are supposed to be limited in a large scalable...
Investigations of magnetic excitations focus on new magnetic materials, quantum magnetism, superconductivity, heavy-fermion or low-dimensional systems, frustrated and multiferroic materials. The challenges of high-resolution studies can be answered only by cold neutron (TAS) spectroscopy experiments.
In our days, there is a trend for extreme conditions, searching for exotic spin states. The...
Polysulfobetaine (PSB) films serve as promising antifouling coatings [1]. In addition, metal-coated thin polymer films hold also tremendous potential for antifouling and antibacterial applications [2]. However, the exact limit to how much one may tune antifouling by means of altering the block copolymer nanostructure with a metal sputtered on top of the polymer remains practically unexplored....
Cobalt-free lithium- and manganese-rich layered oxides (Li[LixNiyMn1-x-y]O2, LMLOs) has catalyzed intensive research efforts to determine their structure that could accommodate a relatively large amount of lithium ions. This feature can make the LMLO electrodes more competitive than the conventional Li[NixCoyMn1-x-y]O2 (NCM) cathodes for Li-ion batteries. However, whether LMLOs should be...
Polarized single-crystal diffractometer POLI at MLZ employs non-polarized double-focusing monochromators in combination with high-efficiency 3He cell polarizers, which lead to a gain in both flux and resolution in comparison with other short-wavelength polarized neutron diffractometers using Heusler-alloy monochromators. With flexible instrument setups, namely: 1) classical single crystal...
With the rapid development of wireless information communication products, electric vehicles, power tools and other fields, higher requirements are placed on the energy density, power density and lifetime of lithium-ion batteries. Compared with conventional graphite anodes, SnO2 afforded much higher theoretical specific capacity (1494 mAhg-1). However, the big volume change and the...
Neutron radiography and tomography are very efficient imaging techniques that allow visualization and study in-situ the kinetics and major effects of primary freeze-drying. The methods complement the classical measurement techniques in freeze-drying that only indirectly obtain the relevant information based on the measurement of usually pressure and temperature. The main advantage of neutron...
High Resolution Powder Diffractometer SPODI
Poly(N-isopropylacrylamide) (PNIPAM) in aqueous solution forms stable dispersions of mesoglobules upon heating through the cloud point. At atmospheric pressure these mesoglobules are small and strongly dehydrated, and their further growth and coalescence are hindered by the viscoelastic effect. On the contrary, at high pressures, larger clusters of PNIPAM mesoglobules are formed, which are...
Neutron single crystal diffraction provides an experimental method for the direct location of hydrogen and deuterium atoms in biological macromolecules, thus providing important complementary information to that gained by X-ray crystallography. At the FRM II the neutron single crystal diffractometer BIODIFF, a joint project of the Forschungszentrum Jülich and the FRM II, is dedicated to...
Electrical steel sheets are used in electric drives to guide the magnetic field. The efficiency of an electrical steel sheet strongly depends on the amount of energy lost during the reversal of magnetization, which is dependent on the mobility of the magnetic domains. The mobility of the magnetic domains is influenced by stress caused during the manufacturing process. [1],[2].
To probe the...
The cold neutron imaging beam line ANTARES at FRM II is a state of the art facility which combines excellent beam properties with highly flexible experimental conditions. User experiments can be performed with complex sample environment like croystats, furnaces or tensile rigs.
In this poster we give an overview of the beam line layout and possible options of the beam line. Moreover, we will...
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...
DNS is a polarised high intensity cold-neutron time-of-flight spectrometer at MLZ. It is situated between MIRA and SPHERES on neutron guide 6 and uses a wavelength between 2.4 Å and 6 Å. DNS has the capability to allow unambiguous separations of nuclear coherent, spin incoherent and magnetic scattering contributions simultaneously by polarization analysis over a large range of scattering...
RESI is the single crystal diffractometer for medium-sized and complex structures wiht thermal neutrons.
The diffractometer RESI is designed for high q-resolution, low background and best flux usage allowing optimum measurements of weak diffraction phenomena in a large portion of the reciprocal space on single crystalline samples.
- Structure analysis, bonding theory, electron densities:...
KWS-3 is a very small angle neutron scattering diffractometer operated by JCNS at Heinz Maier-Leibnitz Zentrum (MLZ) in Garching, Germany. The principle of this instrument is one-to-one imaging of an entrance aperture onto a 2D position sensitive detector by neutron reflection from a double-focusing toroidal mirror. In current state, KWS-3 is covering Q-range between 3·10^{-5} and...
With rising importance of renewable energy sources the need for reliable energy storage-solutions grows. Most batteries used currently in industry are lithium-ion batteries (LIBs) with liquid electrolytes. Due to the inflammable nature of liquid electrolytes LIBs are prone to dangerous damage preventable by solid state electrolytes based on polymers. However the ionic conductivity still needs...
Mesoporous titania films with ordered nanostructures show great promise in various applications, such as solar cells. To optimize solar cell performance, pre-synthesized crystalline germanium nanoparticles around 10 nm are introduced into mesoporous titania films. The influence of different calcination atmospheres (air and argon) on the morphology and properties of TiO2/Ge composite films is...
Recently, the efficiencies of non-fullerene organic solar cells (OSCs) with small molecule acceptors rapidly increased to over 16%, which makes OSCs competitive to commercial available solid state solar cells. Except for the active layer, OSC performance is strongly influenced by the quality of anode layer, since it offers a path for carriers transport. Therefore understanding how metal...
Silicon-based electrodes are attractive candidates as anodes for Li-ion batteries due to their high theoretical specific capacity. However, repeated lithiation/delithiation causes significant morphological changes of the silicon particles which results in formation of highly porous silicon structures and severe side reactions at the silicon/electrolyte interface. To quantify such...
The neutron instrumentation at the MLZ, in particular Small Angle Neutron Scattering, reflectometry and macromolecular crystallography allow to investigate structures in the range from 1 nm up to several hundred nm in reciprocal space. In soft matter and biology the contrast between hydrogen and deuterium is used to gain deep and quantitative insights about the shape and interactions of the...
In organic photovoltaics, donor - acceptor bulk heterojunctions are often used as active materials due to their superior performance compared to e.g. planar layered 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 [1].
A...
Two dimensional angular correlation of annihilation radiation (2D ACAR) is a powerful probe for the investigation of the electronic structure of materials. In ACAR a 2D projection of the two-photon momentum density is recorded, which is closely related to the electron momentum density. From a series of such measurement at different projection angles the 3D Fermi surface(s) can be...
STRESS-SPEC is the dedicated diffractometer for materials science applications at MLZ. It offers high thermal neutron flux and is mainly used for fast residual strain and texture (bulk, local or gradient) measurements [1, 2]. Recent upgrades include a new detector system developed in-house, a new fully automatic slit system for gauge volume definition of the monochromatic beam, and a quenching...
Classic zwitterionic poly(sulfobetaine)s, poly(4-((3-methacrylamidopropyl)dimethyllammonio)butane-1-sulfonate)) (PSBP)， which exhibit an upper critical solution temperature (UCST) in aqueous media，have been widely used to investigate its swelling/deswelling behavior and phase transition mechanism. Also its block copolymers reached high attention if they contain other broadly studied nonionic...
PEDOT:PSS is the most studied conducting polymer system owing to their intrinsically high electrical conductivity, low thermal conductivity, and high mechanical flexibility in thermoelectric devices. The energy conversion efficiency of a TE material is evaluated by a dimensionless figure of merit ZT and defined as ZT=S2σT/k where S is the Seebeck coefficient, σ is the electrical conductivity,...
The PERC experiment is currently under construction at the new beam port MEPHISTO at the FRMII. It aims to measure correlation parameters in neutron beta decay with an accuracy improved by one order of magnitude to a level of $10^{-4}$.
The author will present an overview of the demanding experimental constraints for this precision experiment, concerning the beamline with its’ neutron optical...
Neutron spin echo (NSE) spectroscopy provides the ultimate energy resolution in quasi-elastic thermal and cold neutron scattering spectroscopy. In 2017 the Jülich neutron spin echo at MLZ went through a refurbishment of the secondary spectrometer: The old normal conducting main-precession coils have been replaced by a new set of fringe-field compensated, superconducting magnets that were...
The neutron induced positron source in Munich (NEPOMUC) at FRM II/MLZ provides a positron beam with the world highest intensity of about 10$^9$ moderated positrons per second. The instruments at the positron beam facility are operated as user facility. Low-energy positron beams are applied in a large variety of experiments in condensed matter physics and materials science as well as in atomic...
Neutron Depth Profiling (NDP) is a non-destructive method to probe concentration profiles of specific light nuclides (mainly Li-6, B-10, N-14) in different host materials. The energy loss of the charged particles produced upon neutron capture of the investigated nuclei is correlated to origin of depth and their signal intensity to concentration amount. Here, depth resolutions down to 5 nm can...
Compared to the well-investigated poly(N-isopropylacrylamide) (PNIPAM), Poly(N-isopropylmethacrylamide) (PNIPMAM) has a higher phase transition temperature (43 °C instead of 32 °C). This may be due to the presence of the additional methyl groups on the vinyl backbone, which lead to steric hindrance and weaken the intramolecular interactions. To understand how these effects influence the...
Having no charge, neutrons can easily penetrate the atomic nuclei. The characteristic radiadion of the actication products is ideal for the non-destructive determination of the elemental composition.At MLZ, neutrons are used for chemical analyses in various ways. We present an overview of the different methods regarding their advantages, limitaions and applications. The focus is on the...
The polymers poly(3-hexylthiophene), poly(3-thiopheneacetic acid), poly(3-thiopheneethanol) and the related copolymers are prepared starting from the respective monomer units by chemical oxidative polymerization. Graphene has also been oxidized to graphene oxide, which due to its functional groups is much more soluble in organic solvents and forms far more homogeneous layers than pure graphene...
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 report on the recent progress in the development of the longitudinal MIEZE (Modulation of IntEnsity with Zero Effort) technique at the resonant neutron spin echo spectrometer RESEDA [1] at the Heinz Maier-Leibnitz Zentrum. The key technical parameters, such as the large dynamical range and possible sample environments are discussed. Typical experimental data comprising quasi-elastic and...
Total Reflection High-Energy Positron Diffraction (TRHEPD) has been established as an ideal technique to determine the atomic positions of the topmost and immediate subsurface crystalline structure with highest accuracy. 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...
REFSANS is the horizontal TOF reflectometer at the MLZ in Garching. It is designed to enable reflectometry and GISANS studies of solid/liquid, solid/air and liquid/air interfaces. By using a white incident neutron beam and TOF analysis, REFSANS gives simultaneous access to a range of Q values, which is especially useful to study air-liquid interfaces or kinetic phenomena.
A six chopper system...
The addition of Ca to Mg can improve the creep resistance at elevated temperatures and the mechanical properties of Mg alloys at both room and high temperatures. In current study, the in-situ compressive deformation behaviors of solution treated Mg-0.5Zr and Mg-0.3Ca-0.5Zr alloy were investigated both at room and elevated temperatures (~200°C) at STRESS-SPEC. Cylindrical samples with 6 mm in...
Poly(2-alkyl-2-oxazoline)s (POx) feature tunable thermoresponsive properties and good biocompatibility, which make them suitable for biomedical applications, e.g. as drug carriers. In the present work, two POx-based molecular brushes, featuring PMeOx-b-PBuOx block copolymer side arms densely grafted on a poly(methacrylic acid) backbone, are investigated in aqueous solution. Whereas the...
Single crystal diffraction (scd) 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.
At very high temperatures studies on Nd2NiO4+δ...
The Materials Science group consists of more than 30 people working in a variety of fields related to the applied materials science. Members of this group belong to neutron scattering or positron spectroscopy instruments including the staff acquired through 3rd party funding and the group of fuel cell development. Each month a group meeting is organized to exchange the activities of the group...
Because of high energy density, competitive working voltage, minimum self-discharge, and limited maintenance requirements, rechargeable lithium-ion batteries (LIBs) have been applied in various fields and regarded as the most promising power devices in the future. Due to high theoretical capacity (2152 mAh g-1), germanium oxide (GeO2) is regarded as a promising alternative anode material for...
Austempered ductile iron (ADI) is an attractive material with excellent mechanical properties, like high strength, good ductility, wear resistance and fatigue strength. Its mechanical properties are largely determined by the ausferritic microstructure which contains retained high carbon enriched austenite. The retained austenite will become unstable under plastic deformation and will transform...
Mixed organic-inorganic hybrid perovskite solar cells have shown a promising future because of their outstanding photoelectric performance. The power conversion efficiency (PCE) of perovskite solar cells (PSCs) reached the champion value of 24.2 %, making this technique competitive with commercial silicon solar cells. Despite all these advantages, the application of PSCs is currently limited...
With hydrogen as energy carrier, hydrides are in the focus of research for the application of energy storage and energy transportation. Within the complex hydrides, the metal hydride composite Mg(NH2)2 + LiH has recently gained in importance because of good properties for reversible hydrogen storage. Mg(NH2)2 + LiH has faster de- and rehydrogenation kintetics with the addition of LiBH4. So far...
The preparation of block copolymer nanocomposite films that consist of nanoparticles (NPs) with diameters (D) of more than 10 nm is a challenging task. Herein, ultrahigh molecular weight (UHMW) linear polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) diblock copolymer was spin-coated as a template for the self-assembly of large iron oxide NPs (D = 27 nm), and the morphology of hybrid...
Printing of active layers of organic solar cells is one possible way to overcome the challenge of up-scaling, which is the main drawback in the field of organic photovoltaics on their way to marketability. Thin layers of PBDB-T-SF:IT-4F, a conjugated high-efficiency polymer and a non-fullerene small molecule acceptor, which can achieve a power conversion efficiency of 13 % are printed with a...
The diblock copolymer PMMA-b-PNIPAM forms micelles in aqueous solution that exhibit a reversible shell collapse transition at the lower critical solution temperature (LCST). This thermo-response can be moderated by introducing organic cosolvents such as methanol, ethanol or acetone. In thin film configuration, their multi-responsive behavior makes NIPAM-based polymers promising systems for...
We present the features of the instrument SANS-1 at MLZ, a joint project of Technische Universität München and Helmholtz Zentrum Geesthacht. Measurements of the beam profile, divergence, flux and polarization are given for various positions along the instrument and agree well with simulations. SANS-1 features two interchangeable velocity selectors with 10% and 6% Δλ/λ and a TISANE 14-window...
Current state of the art lithium ion batteries typically use graphite as an anode material. Understanding the dynamical processes during lithiation and delithiation is crucial for comprehending performance and degradation. Especially due to the detrimental effects of fast charging or charging at low temperatures. Many aging processes, like lithium plating, depend intrinsically on the...
Polymer-based organic solar cells (OSCs) are of rising interest in research and industry due to their potential advantages such as light-weight, flexibility, semi-transparency and low production cost. The power conversion efficiency of OSCs has been significantly improved in recent years, by now up to about 15 %. Yet scalability is a still major factor to make OSCs economically viable....
Polymer based films are of high practical use, e.g. as coatings, biomedical applications or flexible electronics. In combination with inorganic materials, this films form interesting hybrid systems of elevated performance, joining advantages of both material classes: Solution processing providing possibilities of cheap industrial fabrication and inorganic characteristics like enhanced...
In times of constantly increasing energy demand, climate change and scarcity of fossil resources the need for renewable energies and the reduction of energy dissipation is of immense importance. Therefore, thermoelectric materials are of great interest in terms of waste heat recovery and the use of solar thermal energy, as they enable the direct conversion of a temperature gradient into...
Understanding the interface between metals, commonly used as current collectors, and ion-conducting polymers used in polymer lithium-ion batteries (LIBs) is crucial to develop highly reproducible, low-cost and reliable devices. To address these issues, sputter deposition is the technique of choice to fabricate scalable, reproducible, and controllable nanometer and sub-nanometer metal layers on...
The KWS-1 small-angle neutron scattering instrument is operated by JCNS at MLZ. 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 and a high resolution owing to its neutron selector with an optional double-disc chopper to reduce the wavelength spread down to Δλ/λ = 1% [1]. This allows study of feature sizes from 10 to 9000 Å. The...
The conversion of energy out of sunlight is an indisputably promising possibility to tackle the problem of the continuously growing energy demand. Thereby, organic photovoltaics (OPVs) have attracted considerable attention, due to their outstanding characteristics, such as potential low-cost fabrication, high throughput, light weight, flexibility and easy processability. Fabrication techniques...
We report on a study of critical scattering in classical and nearly quantum critical antiferromagnets (AFMs). The energy width of the critical scattering was determined by high-resolution neutron spin-echo at TRISP at the MLZ in Munich. The classical systems studied include the s=5/2 AFMs Rb2MnF4 and MnF2 with quasi 2D and 3D spin interactions, respectively. Both compounds are Heisenberg AFMs...
Mesoporous titania have been extensively studied owing to their high surface area, unique electronic and optical properties and applications in photocatalysis and dye sensitized solar cells[1]. An optimal mesopore size of the nanostructured titania film plays a significant role in the device efficiency improvement.
In this work, the bottom up approach of sol-gel synthesis has been used to...
Electronic skin (E-skin) as the medium between ambient environment and bionic robots is an advanced technology that provides an electronic readout or even produces a visualized response that can be easily captured for post-processing. Since this concept birth, different electronic skins have been fabricated and utilized for various sensing applications, such as pressure, humidity, temperature...
Alloy 718 has been widely used in gas turbine and related applications due to its good mechanical properties and structural stability at elevated temperatures (650 °C). The operation temperature of the alloy 718 is limited because of the transformation of the metastable strengthening γ’’ phase to stable δ phase at high temperature. A new 718-type Ni-Co based superalloy VDM 780 Premium was...
The goal of this project (BMBF INA780) is the implementation of an innovative testing machine to perform deformation experiments at high temperatures at various instruments at the research neutron source Heinz Maier-Leibnitz. With neutron diffraction, small angle scattering and radiography (tomography) it is possible to investigate forming phases, their volume fractions as well as size and...
KWS-2 is a classical small angle neutron 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 1 x 10-4 and 0.5 Å-1.
The instrument is designed for high intensity studies with a broad q-range, covering mesoscopic structures and their changes due to kinetic processes...
The investigation of stimuli-responsive organic thin films, which are sensitive to changes in temperature, humidity or other conditions, requires defined environmental conditions at the sample position. Especially in combination with neutron scattering techniques, such as grazing incidence small angle neutron scattering (GISANS) or neutron reflectometry (NR), high requirements to the sample...
To investigate inhomogeneous defect distributions e.g. close to fatigue cracks or dispersive alloy with positron annihilation lifetime spectroscopy a pulsed positron beam with a diameter in the range of 1 µm and with a time resolution in the order of 250 ps is needed.
To this aim the Scanning Positron Microscope (SPM) was built at the Universität der Bundeswehr. To overcome the limit of low...
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...
Cold triple-axis spectrometers (TAS) are dedicated to the investigation of low-energy excitations in a wide area of condensed matter physics, from quantum magnetism to unconventional superconductors. This technique allows us to measure individual points in the large (Q,E) space for one instrument setting, at low temperatures and high magnetic fields. New engineering solutions are being...
Morphology Tuning of ZnO Nanostructures for Hybrid Solar Cells
Hybrid solar cells have attracted great attention due to the advantages of their short payback time, high stability and flexibility, which results from the combination of inorganic and organic materials. For hybrid solar cells, DSSCs (solid-state dye-sensitized solar cells) and HBSCs (hybrid bulk-heterojunction solar cells) are...
1Technische Universität München, Physik-Department, Lehrstuhl für Funktionelle Materialien, James-Franck-Str. 1, 85748 Garching, Germany
Today, one of the biggest challenges is the development of carbon-neutral energy technologies. Solar cells have been a frontrunner for eco-friendly energy conversion for a long time, but in search for better energy conversion and cheaper production, new...
The SPectrometer for High Energy RESolution (SPHERES) at MLZ is a third generation backscattering spectrometer with focusing optics and phase-space transform (PST) chopper. It provides high energy resolution with a good signal-to-noise ratio. Over the recent years different components of the instrument have been upgraded to further improve the instrument performance.
SPHERES enables...
A pair-plasma, a system where both the positively and negatively charged particles have the same mass, is predicted to possess unique physical properties. The APEX collaboration attempts to magnetically confine the first low-temperature electron-positron pair plasma in the magnetic field of a levitated superconducting coil. In a prototype experiment, positrons provided by the NEPOMUC facility...
The need for rapid data collection and studies of small sample volumes in the range of mm3 are the main driving force for the concept of a high-throughput monochromatic diffraction instrument at the Heinz Maier-Leibnitz Zentrum (MLZ). A large section of reciprocal space will be addressed with sufficient dynamic range and µs time-resolution while allowing for a variety of complementary sample...
The use of operando diffraction has taken a major step forward, in no small part due to the increase in flux at large scale facilities such as synchrotrons and neutron spallation sources. While the X-rays are absorbed by the battery casing which necessitates special cells with windows, neutrons have a penetration depth large enough to probe the entirety of cell. This has allowed measurements...
Ni-based superalloys are used for high temperature (T) applications that require good mechanical properties, as gas turbines. Among these alloy 718 is the most widely used with operation T up to 650 °C. In this alloy the austenitic matrix is strengthened by $\gamma$’l and $\gamma$’’ precipitates. Other phases that can be formed are $\delta$ and $\eta$. The existence of the different phases,...
The development of new high temperature superalloys for aircraft engines and stationary gas turbines in power engineering requires higher service temperatures to enhance efficiency and reduce CO2 emissions.
The development of these new materials require the structural (phase transformation) and mechanical (hardness) studies of strengthening and high temperature phases, precipitation kinetics...
Molecular Beam Epitaxy (MBE) is a versatile tool to fabricate high quality and high purity epitaxial thin films with low intrinsic defect concentrations and atomic-layer control.
At the 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...
The Nickel Alloy 718 was developed in the 60’s for aerospace applications but due to its good corrosion resistance in sour gas application combined with the excellent strength properties, it found huge application in the Oil & Gas industry. Alloy 718 is a precipitation hardenable nickel-alloy enriched with amounts of niobium, molybdenum, titanium and aluminum, which combined grant the good...
SAPHiR, the Six Anvil Press for High Pressure Radiography and Diffraction belongs to the suite of new instruments that are located in the neutron guide hall east of FRM II. The aim of SAPHiR is to provide extreme pressure and temperature environments for polycrystalline samples, fluids, or melts. The pressure is generated by a three-axis multianvil press with a combined force of 2400 tons (24...
The newly developed polycrystalline Co-base-superalloy CoWAlloy2 (Co41Ni32Cr12Al9W5 + Ti,Ta,Si,C,B,Zr,Hf) provides a high potential for application as wrought alloy due to the large gap between solidus and gamma'-solvus temperature along with a high gamma'-volume fraction. The scope of this study was the improvement of the high temperature strength by optimizing the gamma/gamma'-microstructure...
Like other Co-based superalloys presently used in gas turbine static components, the Co-Re alloys use Cr to provide oxidation resistance [1]. Cr addition above 20 at.%, however, pose a challenge – namely the formation of topologically closed packed Cr2Re3-type σ-phase. It is generally avoided in high-temperature alloys as its presence causes brittleness. To improving oxidation resistance and,...
The cold-neutron three-axis spectrometer MIRA is an instrument optimized for low-energy excitations. Its excellent intrinsic 𝑄-resolution makes it ideal for studying incommensurate magnetic systems (elastic and inelastic). MIRA is at the forefront of using advanced neutron focusing optics such as elliptic guides, which enable the investigation of small samples under extreme conditions. Another...
The Pulsed Low Energy Positron System (PLEPS) at the intense positron source NEPOMUC at the MLZ in Munich allows to measure positron lifetime spectra using a mono-energetic positron beam of variable energy between 0.5-20 keV. PLEPS is a unique tool to investigate open volume defects in a large variety of material systems, e.g. in wide bad-gap semiconductors or in thin layer structured...
Diffusion is a fundamental property of liquid with a high importance to many aspects in physics and material science. Despite its technical relevance it’s still not very well understood how atomic diffusion depends on properties, like the atomic mass, molar volume, and the melting point. The lack of internal degrees of freedom and the short-range, repulsive nature of metallic bonds make pure...
Cycling stability and capacity fading of Li-ion batteries are highly relevant for their application. A plenty of mechanisms directly leading to the capacity losses upon cycling are known, e.g. formation of passivation layers, losses of cyclable lithium etc. Typical Li-ion cells are characterized by non-uniform distributions of current, temperature and gradients in electrolyte and lithium...
The development of all-solid-state batteries as high power and energy density storage devices has become one of the key challenges in solid-state chemistry and material science. Not only improvement of current electrode and electrolyte materials as well as the cell architecture, but also the search for new compounds is necessary to get access to a new generation of all-solid-state battery...
Regarding to that lithium-ion batteries are seldom used at the entire state of charge (SoC) interval for the vehicular usage conditions, investigating the battery fatigue mechanisms at different using SoC ranges could guide the battery management. 18650-type cells are cycled at various SoC intervals. In situ methods, e.g. differential voltage analysis (dV/dQ), neutron power diffraction (NPD),...
Solid oxide fuel cells (SOFCs) offer a promising green technology of direct conversion of chemical energy of fuel into electricity. Barium cerates with Y-substitution at the Ce site, BaCe1−xYxO3−δ, are well known for excellent conduction capabilities in the temperature range 400–800 °C as a result of the proton motion in the crystal lattice. We report on oxygen-deficient BaCe0.85Y0.15O3−d...
In the present work, we report the results of an unpolarized small-angle neutron scattering (SANS) study on MZFO nanoparticles with the aim to elucidate the interplay between their particle size and the magnetization profile. Here, Mn0.2Zn0.2Fe2.6O4 nanoparticles covered with a thin layer of oleic acid (capping agent) were synthesized by co-precipitation or thermal decomposition. The chemical...
The high resolution/polarization 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...
NICOS (Networked Instrument COntrol System) is the general user interface to
control the instruments at the MLZ. NICOS is now in use at 23 instruments.
A number of standard commands exist, and instrument specific commands are
possible.
Python is also used as the command and scripting language.
There is a script execution component, components to create a history of
measured data as well as...
NECTAR is a superior 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, gamma rays are produced in the same process. The production of these gamma rays is inevitable as they are inherent with...
POWTEX is a TOF neutron powder diffractometer under construction at MLZ. Funded by Germany’s Federal Ministry of Education and Research (BMBF), it is built by RWTH Aachen University and FZ Jülich, with contributions for dedicated texture sample environments from the Geo Science Centre of Göttingen University.
An instrument overview and the advances made in neutron instrumentation will be...
Doppler broadening-spectroscopy (DBS) of the $511 \textrm{keV}$ gamma line, generated by positron-electron-annihilation, provides information on lattice defects, sensitive to concentrations as low as 1e-7 vacancies per atom. In addition the chemical surroundings of defects can be analyzed by coincident DBS (CDBS). The CDB-Spectrometer at the Neutron-induced Positron Source Munich (NEPOMUC) is...
