The new twist in GISANS experiments aims at - for neutrons - relatively fast kinetics and processes in the time domain of 1h and below. Examples range from spray deposition over vapor exposure to tempering processes being all important for industrial applications. The considerably different contrast for neutrons adds valuable complementary information to the much faster GISAXS experiments. Due...
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...
A new multianalyzer Bambus is being constructed at Panda, MLZ. The objective is to construct broad reciprocal space maps at multiple energy transfers, in order to get insights of broad features at low energy or study complex dispersion laws. Because this spectrometer is designed as a complementary option to the normal TAS mode, a fast switch between the two setups is foreseen. The general...
Over the last decades organic electronics (OE) have attracted the focus of research due to their advantageous properties. Advantages, such as the flexibility of OE, the ease of processablility and the applicability of industrial up-scalable and low-cost processing methods, open up a wide range of possible application fields. Especially organic photovoltaics (OPV) have drawn much attention, due...
Capillary breakup extensional rheomerty (CaBER) as a method for investigating short-time relaxation mechanisms and extensional properties of soft matter has immensely gained in importance since its invention almost 40 years ago. Despite its widespread use, this method has never been combined with high resolution in-situ structural investigations such as small angle scattering.
We demonstrate...
Self-assembly is the phenomenon of spontaneous organization of nanoparticles into a stable 1D, 2D or 3D assemblies on a substrate or in solution. Understanding the origin of self-assembly will allow us to harness unique properties of the material that are both multifunctional and adaptable with applications in various fields of biomedical engineering and material science. Self-assembly of...
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...
Silicon-graphite (SiG) electrodes are attractive candidates as anodes for Li-ion batteries due to their high theoretical specific capacity. However, repeated lithiation/delithiation during charge/discharge cycling causes significant morphological changes of the silicon particles. This results in the formation of highly porous silicon structures and severe side reactions at the...
To support the global nonproliferation efforts, FRM II is actively working towards the conversion of its compact fuel element to a uranium enrichment, which is significantly lower than its current enrichment of 93%. Thereby, it is of utmost importance that the scientific performance does not suffer and that such new fuel element fits in the current core geometry to provide a continuous...
Nowadays, there is a lot of hype around big data, machine learning, deep learning. It is used by autonomously driven cars, in marketing for product recommendation or by search engines. The technique is very powerful. Could we apply it to neutron scattering data? Are the event-mode data from the PSD detector “big”? Can the neural network learn from it? What does the neural network learn and...
In addition to providing day-to-day maintenance and service, the detector and electronics group of the MLZ is engaged in the development and construction of new detector systems. We will present results from our current major project, a 130-degree curved multi-wire proportional counter for the upcoming diffractometer instrument ERWIN, as well as details on other ongoing work.
Modern neutron sources deliver high fluxes of neutrons. Most current detector technologies therefore need to shield the primary beam, or cannot use the full dynamic range of the neutron flux. Therefore we created the Solid-State Neutron Detector (SoNDe).
SoNDe is a project for the development and construction of a high-flux capable neutron detector. The development focuses on the following...
In the last decades Li-ion batteries, occupied an important role in energy market, are widely used in powering portable devices, off-grid energy storage and e-mobility applications. In a number of publications, it was shown that a neutron powder diffraction pattern taken on cylindrical cells like 18650-type can be successfully refined using a contribution from the cell constituencies: positive...
Discussion of new instrumentation based on input by the science groups
Ionic liquids (ILs) are molten salts without additional solvent composed by organic cations and organic or inorganic anions. ILs show very interesting physical-chemical properties, such as high thermal and chemical stability, negligible vapour pressure, low flammability, high ionic conductivity, remarkable solvation capability towards a large variety of compounds, and in some cases even...
The possibilities of neutron scattering and imaging for materials science are perfectly complemented by those offered by high-energy X-rays from a synchrotron source. While neutrons stand out with their large penetration depths and contrast and magnetic properties, the synchrotron offers high enough intensities to achieve sufficient time resolution for studying fast processes. In addition,...
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 study the morphology, electric, magnetic, magneto-electric coupling
and magneto-transport properties of Fe$_3$O$_4$/Nb:SrTiO3(001) and
Fe$_3$O$_4$/PMN-PT(011) heterostructures. Studies like, interfacial capacitance,
magnetic depth profile, ferroelectric ordering, stress and charge
screening-control of the Verwey transition are of special interest. The
Fe$_3$O$_4$ films are grown in an oxide...
Recent developments and perspectives at the MLZ of neutron spin echo spectroscopy instruments are presented.
Due to limited supply of traditional fossil fuels, increasing carbon emission, and deteriorated environmental pollution, it is urgent for humankind to ensure alternative renewable energy sources. 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...
Due to low cost, flexibility, solution processing and large-scale fabrication, enormous attention is focusing on the research and development for higher OPV performance over the last decades. To improve the overall performance of organic photovoltaics, interfacial modifiers are widely applied in the device architecture to facilitate charge collection, tune the distribution of materials, and...
The investigation of thin polymer films with neutrons allows a non-destructive probe on their structure and composition. In the framework of the FlexiProb project, which plans an interchangeable sample environment for different neutron experiments at the European spallation source (ESS), we designed a setup for grazing incidence small angle neutron scattering (GISANS). The new sample chamber...
Dynamic light scattering (DLS) is based on the temporal analysis of the intensity fluctuations of the scattered light caused by the Brownian motion of particles (protein molecules, aggregates, polymer particles etc.) in solution. It provides information on the translational diffusion coefficient, allowing the characterization of particles with average radii in a broad range from a few...
Responsive block copolymer thin films are of interest for many applications, e.g. as fast sensors or switchable membranes. They may be based on physical hydrogels formed by telechelic copolymers featuring a stimuli-responsive midblock and hydrophobic end blocks. For temperature-responsive end blocks, a weak gel is formed below their collapse temperature, while a frozen network is formed above...
Although based on organic materials, organic solar cells often include metal electrodes due to their unrivaled electronic conductivity. Thus, polymer-metal interfaces are inherently present in most OPV devices and have a major influence on their behavior. Understanding the growth mechanisms of metal contacts on polymer thin films plays a crucial role in identifying potential ways to enhance...
The understanding of structure-property relationships is essential for the development and improvement of engineering materials. In-situ characterization of materials under external thermo-mechanical treatment is usually required. The materials science diffractometer STRESS-SPEC is designed to be applied equally to structure, texture and residual stress analyses by virtue of its very flexible...
Resent research in organic photovoltaics focuses on identifying new high-efficiency polymers and acceptor molecules to reach high power conversion efficiencies (PCEs). To date, a PCE of 13% could be obtained with a PBDB-T-SF: IT-4F based organic solar cell device. However, towards commercialization, the solar cell performance must be optimized and an up-scale of the thin layer deposition is...
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...
Control of n-type inorganic morphology, chain orientation and crystallization of the donor polymers is of significance in hybrid solar cells. Here, we use slot-die printing combined with wet chemistry to fabricate controllable mesoporous TiO2 nanostructures in large scale. Subsequently, the mesoporous TiO2 films with different pore size are backfilled with P3HT and PffBT4T-2OD, respectively,...
Bart-Jan Niebuur1, Geethu P. Meledam1, Vitaliy Pipich2, Marie-Sousai Appavou2,
Alfons Schulte3, and Christine M. Papadakis1
1 TU München, Physik-Department, Garching, Germany
2 FZ Jülich, JCNS at MLZ, Garching, Germany
3 University of Central Florida, Orlando, U.S.A.
The thermoresponsive polymer Poly(N-isopropylacrylamide) (PNIPAM) in aqueous solution forms dehydrated, smaller...
The diblock copolymer PMMA-b-PNIPAM in aqueous solution undergoes a reversible coil collapse transition at the lower critical solution temperature (LCST). This characteristic transition temperature can be tuned by the addition of organic co-nonsolvents such as ethanol or acetone. In order to investigate co-nonsolvency behavior in thin film geometry, we perform swelling experiments with a...
D. Gorkov a,b,c, G. Waldherr b, A. Grünwald a,b,c, J. Stein a, S. Giemsa c, P. Böni c, and M. Braden a
a II. Physikalisches Institut der Universität zu Köln, D-50937 Köln, Germany.
b Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München,
D-85747 Garching, Germany.
c Physik-Department E21, Technische Universität München,
D-85747 Garching, Germany
KOMPASS is a polarized...
Large Scale II
The cold triple-axis spectrometer (TAS) FLEXX at HZB is a well-designed and recently upgraded instrument [1-4]. There is a strong wish that this excellent instrument should be preserved for the community after shutdown of the HZB neutron source. One attractive gap in the present instrumentation suite, which could be filled by FLEXX, is the Larmor-diffraction technique [5-6] (LD) and, as a...
Alloys of rare-earth elements and 3d transition metals became recently again in the focus of attention due there rich variety of magnetic effects owed to the different anisotropies of both material classes [1-3].
In this work, various thin film systems containing the amorphous DyxCo100-x alloy will be discussed. Despite of their amorphous nature, the film system show non trivial magnetic...
Phospholipid membranes are the basic construction material of cell membranes. Also, solutions of phospholipid vesicles find a wide array of applications in technical, medical and biological applications. Hence, the basic understanding of these membranes, both in terms of structure and dynamics is of paramount importance in order to better understand the mechanisms of cell membrane...
Neutron specular reflectivity at soft interfaces provides sub-nanometer information concerning the molecular distribution of thin films, while the application of contrast variation permits to highlight the scattering from different parts of the system and can lead to an overall reduction of fitting ambiguity. Traditional modelling approaches involve the construction of a trial scattering...
There are several methods to store hydrogen, e.g. with physical technologies (compression), in metal hydrides or in complex hydrides. Within the complex hydrides, the metal amides Mg(NH2)2-LiH have recently gained in importance. They have good hydrogen storage properties with high capacity (ca. 4 wt%) and good reversibility. The drawback of these materials is the high kinetic barrier for...
Poly(2-alkyl-2-oxazoline)s (POx) are well known for their tunable thermoresponsive properties and good biocompatibility, which make them promising materials for biomedical applications, e.g. as drug carriers. Depending on the type of alkyl substituent, they can be hydrophilic, e.g. poly(2-methyl-2-oxazoline) (PMeOx), thermoresponsive, e.g. poly(2-ethyl-2-oxazoline) (PEtOx) and...
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 postprocessing. Since this concept birth, different electronic skins have been fabricated and utilized for various sensing applications, such as pressure, humidity, temperature...
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 [1], as well as neutrons interacting with beamline geometry, such as the collimator, gamma rays are produced in the...
Introduction in my work
Neutron activation analysis is a nuclear analytical technique mainly used for the determination of trace elements. NAA is typically applicable to the chemical elements from the 4th period of the Periodic Table, and is highly sensitive for Na, Mn, Sc, Ta, Ir, In as well as the rare-earth elements. Its advantage is simple sample preparation, high sensitivity, non-destructiveness and...
In ferromagnetic quantum critical systems it is possible to suppress the Curie temperature to 0 K by changing an external control parameter such as a magnetic field or hydrostatic pressure. Recent theories suggest a generic phase diagram for clean quantum critical ferromagnets featuring a tricritical point where the order of the phase transition changes from 2nd to 1st. This behavior has...
In collaboration with Idaho National Lab, several dozens of new scintillation screens for neutrons were tested at FRM II.
Existing mixtures with LiF were tested, but also new mixtures with boron, which were very promising on the way to higher spatial resolution in neutron imaging. A third class comprised dysprosium-doped screens which are not only more sensitive in the epithermal range for a...
The question on the nature of dark matter is one of the major challenges of particle physics. So it is clear that the possibility of a dark decay channel as a solution to persisting discrepancies in measurements of the neutron lifetime using different techniques initiated massive research activity. In this presentation we will discuss recent results by PERKEO which largely rule out this interpretation.
Organic-inorganic metal halide perovskite solar cells (PSCs) offer a potentially cheap source for clean and low cost electrical energy. Improving stability1, 2 and minimodule power conversion efficiencies over 17% in 20183 promise commercial devices possibly capable of competing with multi-crystalline silicon solar cells with current module efficiencies of around 22% in 20173. This calls for...
Powder diffraction is the experimental technique, which stands on the forefront of the material characterisation, delivering the key information about the crystal structure. Being perfectly parametrized and standardized technique, the powder diffraction is in broad use and X-ray powder diffractometer is a part of equipment in nearly every lab specializing on materials research.
Neutron powder...
Thermo-responsive polymers can show a strong change in volume towards even slight changes of their surrounding temperature. This behavior makes them promising candidates for the implementation in a manifold application fields such as nano-sensors, artificial pumps and muscles, or optical switches. While the underlying mechanisms of such polymers in solution are well understood, less is known...
Under the general name of “polarised neutron diffraction” indeed a variety of different experimental techniques are usually meant. Those are: classical polarised neutron diffraction (PND) called also Flipping-Ratio method or also in the recent years: Half-polarised neutron diffraction, this technique uses strong magnetic fields (> 1 T) on the sample position. Another method is Linear or...
In 2017 the Neutron Spin Echo (NSE) Spectrometer went through a refurbishment of the secondary spectrometer. A set of superconducting precession coils was realized following the results obtained for the design of ESSENSE, the proposed high-resolution NSE spectrometer at the ESS. One of the most innovative characteristics of the coils is their optimized geometry that maximises the intrinsic...
Diffraction and imaging using X-rays and neutrons are widely utilized in different fields of engineering, biology, chemistry and/or materials science. Combined information gained by X-ray diffraction computed tomography (XRD-CT) is a powerful approach with high potential due to enhanced sensitivity of the method. Its active development over the last decade revealed structural details in a...
Photosynthesis is the key mechanism in utilization of solar radiation for living organisms and thus provides the base for most food chains and all fossil fuels. The functionality of photosynthetic proteins is -in part- critically influenced by dynamics on a timescale of pico- to milliseconds and on sub-nanometer length scale. The neutron time of flight spectrometer TOFTOF at MLZ-Garching is...
We report neutron scattering and AC magnetic susceptibility measurements of the 2D 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 a up-up-down-down strip structure. Dominant magnetic diffuse scattering and comparison to published μsr measurements indicates that the remaining 66% is fluctuating. This demonstrates...
Quantum dots (QDs) with near infrared emission are promising for use in photodetectors (PDs) for sensing and in photovoltaics (PVs) for solar energy conversion. High quality QDs are normally synthesized in solution and capped with organic ligands. To efficiently functionalize the QDs’ array for PD or PV devices, the ligand exchange treatments, in solution or on solids, to colloidal QDs are...
Yixi Su$^1$, Xiao Wang$^1$, Fengfeng Zhu$^1$, Junda Song$^1$, Viviane Pecanha-Antonio$^1$, Erxi Feng$^1$, Thomas Müller$^1$, Thomas Brückel$^2$
1Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich, D-85747 Garching, Germany
2Jülich Centre for Neutron Science (JCNS) and Peter Grünberg Institute (PGI), Forschungszentrum Jülich, D-52425...
Introduction of my work
A dedicated polarized neutron diffraction (PND) setup, using a symmetric-field high Tc superconducting magnet with a maximal field of 2.2 T in combination with a ³He polarizer and Mezei-type flipper, has been developed at the instrument POLI. Each component is optimized by numerical simulations and the complete setup is successfully tested and calibrated.
This new PND setup was used to...
How to develop an innovative process for efficient and high-quality development of advanced materials and components?
The EU-Horizon2020 project SINE2020 aims at strengthening the cooperation between industry and European neutron sources. Free of charge, the project offers training and education of industrial researchers and the possibility to perform test measurements at the participating...
An oxygen vacancy induced topotactic transition from perovskite to brownmillerite and vice versa in epitaxial La0.7Sr0.3MnO3-δ thin films is identified by real-time x-ray diffraction. A novel intermediate phase with a non-centered crystal structure is observed for the first time during the topotactic phase conversion which indicates a distinctive transition route. Polarized neutron...
Within the scope of this thesis, we modified and tested the new experimental set up for measuring Total Reflection High-Energy Positron Diffraction (TRHEPD [1]) and Reflection High-Energy Electron Diffraction (RHEED). The remoderated positron beam from NEPOMUC will be used for investigation of surface reconstructions with topmost atomic layer sensitivity.
In order to benchmark the RHEED...
Stripe ordered La2-xSrxM(M=Cu,Co,Ni)O4+𝛿 oxides have been investigated intensively, as one of its family member La2CuO4+𝛿, showing the similar electronic ordering, gets superconducting at low temperature. A very special excitation of the ordered/disordered spin-stripes, shaped like an ‘hour-glass’, is discussed to be an important signature for the appearance of superconductivity. So far to...
Very frequently in soft matter studies at the solid liquid interface and in an effort to reduce the ambiguity of the model that is used for fitting neutron reflectivity experimental data, arises the need for the manipulation of the scattering length density of the solvent (usually water). Manual exchange of solvent is laborious while the control of the rate of solvent exchange is difficult....
The preparation of block copolymer (DBC) nanocomposite films that consist of magnetic nanoparticles (NPs) with diameters (D) of more than 10 nm is a challenging task. In the present work, this limitation is addressed by using an ultrahigh molecular weight (UHMW) DBC polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) as templates for the self-assembly of periodic hybrid materials...
The thermal triple-axis-spectrometer PUMA is one of the most robust and yet extremely flexible instruments worldwide of its kind. In addition to the 'normal triple axis' set up, PUMA delivers a good number of unique features to meet the ever growing demands of the scientific community worldwide. One of them is the multiplex system, which consists of eleven arbitrarily configurable...
Following the recent observations of large anomalous Hall effect (AHE) and the possible realisation of magnetic Weyl fermions in the intermetallic non-collinear antiferromagnet (AFM) Mn3Sn, this compound has rapidly emerged as a promising quantum material that may find huge potentials for future information and quantum technologies [1-3]. Geometric frustration in the Kagome lattice of Mn atoms...
We have studied superparamagnetic iron oxide nanoparticles by various experimental techniques in order to characterize the observed reduced saturation magnetization as compared to bulk. Magnetic nanoparticles of the size of 12 nm and 15 nm have been studied by means of small-angle X-ray scattering (SAXS), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM),...
Hybrid solar cells with an active layer based on low temperature processed titanium dioxide and a water-soluble polymer have been developed [1]. In this all-embracing green technology approach TiO2 nanoparticles are produced with laser ablation in liquid in order to initiate a functionalization of TiO2 with the polymer for the active layer. Combining these TiO2 nanoparticles and water-soluble...
Nanostructured polymer-metal-composite films demonstrate great perspectives
for optoelectronic applications, e.g. as sensors or photovoltaics. To enhance properties of such devices the self-assembly process needs to be understood. We studied the cluster morphology growth by grazing incidence small-angle X-ray scattering (GISAXS), as well as the crystallinity of the metal film formation with...
Ferrimagnetic iron oxide nanoparticle monolayers on top of ferroelectric BaTiO3 (BTO) substrates were prepared and a magnetoelectric coupling effect was observed. Grazing incidence small angle X-ray scattering and scanning electron microscopy confirm a hexagonal close-packed supercrystalline order of the nanoparticle monolayers. We employed a magnetoelectric AC susceptibility setup as...
A method for near surface strain scanning measurements using neutron diffraction with large gauge volumes is described and validated against x-ray diffraction (XRD) and neutron diffraction experiments with very high spatial resolution. The approach corrects for pseudo strains related to partially buried gauge volumes and enables to deconvolute the averaging effects associated with the use of a...
Recently organic lead mixed-halide perovskite based solar cells surpassed a power conversion efficiency of 22 %. In particular the unique properties of perovskites, e.g. the highly tunable chemical composition, allow optimizing the hybrid crystal structure in a way to meet the desired demands. To take full advantage of this tunability of the perovskite materials, we apply a 2-step deposition...
Refrigeration based on the magnetocaloric effect is a potential alternative to conventional vapor compression refrigeration. One system of particular interest with regard to application is Mn$_{5-\textit{x}}$Fe$_\textit{x}$Si$_3$ [1-3]. Pressure affects the interatomic distances in the crystal structure and thus has an influence on the magnetic properties.
The aim of this work is to establish...
The rapid development of metal halide perovskite solar cells (PSCs) makes such solar cells power conversion efficiency (PCE) comparable with silicon solar cells and the certified PCE has already reached 23.7%1. However, long-term device stability is one of the most critical issues in PSCs. To improve the stability of PSCs, interface passivation, inorganic materials and encapsulation strategies...
The variation of the magnetic moment with dimensionality of magnetic materials, i. e. from atoms to bulk, is a longtime studied issue. For thin films, a constant magnetic moment is often assumed in modelling, however, intermixing and surface roughness may also have an impact.
With the help of polarised neutron reflectometry (PNR) we study the magnetic moment of polycrystalline Co/20 nm...
Introduction
Due to their high melting point, low density, and good oxidation resistance, γ-TiAl based alloys have recently started to replace Ni-based superalloys as a material for turbine blades in aircraft engines [1]. Conventional γ -TiAl alloys usually contain the ordered phases γ-TiAl and α2-Ti3Al at lower temperatures and disordered α-Ti(Al) phase above 1120°C. Additional alloying...
Asmaa Qdemat1, Emmanuel Kentzinger1, Giuseppe Portale2, Marina Ganeva3, Stefan Mattauch3, Oleg Petracic1, Ulrich Rücker1, Thomas Brückel1
1Jülich Centre for Neutron Science (JCNS) and Peter Grünberg Institute (PGI), JARA-FIT, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
2 Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen,
The Netherlands
3 Jülich Centre for...
Neutron grating interferometry (nGI) is a relatively new neutron imaging technique which is the adaption of a Talbot-Lau Interferometer for neutrons [1]. It simultaneously delivers information about the transmission (TI), phase shift (DPC) and the scattering (DFI) inside a sample [1].
In particular the DFI has generated high interest, due to its ultra-small-angle neutron scattering (USANS)...
Amphiphilic diblock copolymers having a hydrophobic poly(methyl methacrylate) (PMMA) block and a thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) or poly(N-isopropylmethacrylamide) (PNIPMAM) block form core-shell micelles in aqueous solution. The transition temperature of the PNIPMAM block is 43 oC, thus significantly higher than the one of PNIPAM (32 oC), which has been attributed to...
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 becomes due to the functionalization highly dispersible in organic solvents, forms far more homogeneous layers than pure...
Update and discussion of the current status of the time-of-flight spectrometer TOFTOF and the potential transfer of NEAT to MLZ.
Total Reflection High-Energy Positron Diffraction (TRHEPD) has been established as an ideal technique to determine the crystalline structure of topmost and immediate subsurface atomic layers. In contrast to Reflection High-Energy Electron Diffraction (RHEED), TRHEPD features an outstanding surface sensitivity, which stems from the repulsive crystal potential for positrons and the phenomenon of...
Non-fullerene organic solar cells (OSCs) have attracted great interests due to the low cost materials, which make it easier to be commercialized in industries. Despite the power conversion efficiency (PCE) of related devices have been well developed with lab scaled fabrication processes, like spin-coating deposition, the situation for the devices fabricated by industry preferred depositions,...
Rare-earth based triangular antiferromagnets provide a novel playground for frustrated magnetism and quantum spin liquid behavior of spin-orbit coupled moments. YbMgGaO4 features spin-orbit moments from a Kramers doublet, which remain fluctuating down to very low temperatures. We discuss recent inelastic neutron scattering experiments which point at valence bond excitations [1,2].
[1] Y. Li...
Besides the well-known vortex lattice (VL), type-II/1 superconductors exhibit the intermediate mixed state (IMS), where VL domains and Meissner domains coexist, due to an attractive component of the VL interaction [1]. Despite some work in the 1970s, no detailed theoretical model for the IMS exists. Primary obstacles are the inapplicability of most standard models of superconductivity and the...
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 postprocessing. Since this concept birth, different electronic skins have been fabricated and utilized for various sensing applications, such as pressure, humidity, temperature...
Wrap up & Road Map
The understanding of soft and biological materials requires the global knowledge of their microstructural features from the elementary units at the nm scale up to larger complex aggregates, in the micrometer range. Such a wide length scale can be explored at the KWS-2 small-angle neutron (SANS) diffractometer of JCNS [1-3], which was optimized for structural investigations over a wide momentum...
