Most of the established MD water models are optimized to reproduce macroscopic water properties, but are then used to study its nanoscopic structure and dynamics.
Neutron and X-ray scattering experiments investigate matter on exactly this nanoscopic level and these experiments can be used to optimize the water models on exactly the same time- and length-scale they will be evaluated on.
In...
The heteroanionic approach for the design of materials has led to variety of novel systems with unique properties. In particular, heteroanionic hydrides emerged with promising properties themselves. Over the recent years such compounds, in particular hydride fluorides have been thoroughly investigated as potential host materials for rare earth activated luminescence.
Here, the...
Data reduction is a transformation of a dataset collected during a scattering experiment into a dataset in physical units. It requires detailed knowledge of geometry and configuration of the instrument at which the dataset was collected. As a result, data reduction is an essential stage required for linking raw experimental data to a meaningful scientific publication. As such, development of...
Following the discovery of a quantum-limit magnetic Chern phase in
TbMn6Sn6, the magnetic topological metal series RMn6Sn6 (R=Gd-
Yb, and Y, Lu, etc.), that possesses an ideal kagome lattice of Mn, has
emerged as a new platform to explore exotic states and novel functionalities.
We have recently carried out the growth of high-quality single
crystals of the magnetic kagome metal ErMn6Sn6,...
The advent of the new spallation sources as well as the various major upgrade programmes of existing facilities have given great impetus to the new and further development of neutron detection techniques for neutron scattering applications in the last decade. Great progress has been made, particularly in the area of count rate capability and large detection areas.
With regard to the projects...
Additive manufacturing (AM) enables to manufacture of complex shapes ultimately leading to lightweight components. To be certain that the components perform as designed it is necessary to know the types of defects and distributions in the components and their influence on mechanical properties. For this neutron grating interferometry (nGI) can be used to quantify various types of defects and...
We study vacancy-type defects in tungsten mono-crystals using positron annihilation Doppler-broadening and lifetime spectroscopy. These studies are part of nuclear fusion research necessary to predict the durability of reactor walls.
A persistent challenge for the inelastic neutron scattering technique has been the low scattering cross-section of neutrons, necessitating large sample sizes compared to elastic neutron scattering or inelastic x-ray scattering. Focusing the neutron beam is a viable technique to increase the flux reaching the sample, but previous techniques suffer from limitations to beam size, beam quality or...
Let us face it: The research reactor FRM II will experience future shutdown periods of 6 months or longer also in the near and far future be it due to regulatory issues with the local government or be it due to technical problems encountered. In this contribution I would like to show how to mitigate the negative effects of these shutdown periods and to turn them into something productive and...
Attenuation-based radiography and tomography (CT) are well-established experimental techniques for non-destructive visualisation of the object interior, where X-/gamma-rays and neutrons are most commonly used types of the incident radiation, but also protons or heavy particles (e.g. ions) can be used as a source. Different radiation sources are used along with phase-contrast, Bragg and/or...
The waterborne latex films, obtained from the dispersions of latex particles are of particular interest due to the non-content of volatile organic compounds (VOC), which is often mandatory under environmental legislation [1]. However, abrupt water penetration inside the films restricting their lifespan and deteriorating the shining of the coating, limiting their uses [2]. In order to prepare...
The cognitive dysfunctionality stems from Amyloid Aβ (1-42), a neurotoxic peptide which is primarily responsible for Alzheimer's disease and is predominantly found in the extracellular spaces in the form of senile plaques. Aβ42 has a strong propensity to interact with the phospholipid membrane, sphingomyelin, ganglioside GM1, and cholesterol. The plasma membrane is the first biological...
Neutron and synchrotron diffraction studies under mechanical stress in titanium alloys Ti-64 (near α-alloy), Ti-6246 (α+β alloy), Ti-5553 (near β-alloy) and Ti-38644 (β-alloy) were performed to investigate the deformation mechanisms. In particular, the determination of single-crystalline elastic constants derived from the measured lattice strains in the polycrystalline specimens will be...
The electric field driven assembly of highly crosslinked ionic microgels at effective volume fraction, ϕeff=0.04 is studied using a confocal microscope. The isotropic microgels undergo structural transitions depending on the field strength and microgel concentration. At low ϕeff, the ionic microgels interact via long-range Yukawa type interaction and the interparticle separation between...
Anode free batteries are designed to significantly decreases the weight of a cell.They necessitate immaculate reversibility of the charge
and discharge process, as no further lithium other than the amount loaded into the cathode is available. Homogeneous plating and
stripping of lithium onto a current collector is not readily achieved when plating on e.g. on copper. Lithiophilic metals like...
In recent years, the scientific community has witnessed an exponential growth in digitalization, presenting unprecedented opportunities for advancements in neutron science. This abstract aims to highlight the importance of embracing digitalization and incorporating cutting-edge technologies, specifically focusing on the utilization of artificial intelligence (AI) and other emerging "hot...
Event mode neutron imaging detectors generate information for every neutron hitting the detector individually. This allows the usage of algorithms to analyze the individual events and improveme noise supression as well as temporal and spatial resolution. The detector have already been tested sucessfully for fast, thermal and cold (ToF) imaging, and neutron diffraction.
High-resolution neutron radiography requires an imaging system capable of detecting the exact location of the absorbed neutrons in the scintillator screen. This is realized by a sensitive CMOS camera with high frame rate capabilities and an image intensifier, which is able to amplify the weak light output created by individually absorbed neutrons. Identifying and recording single neutron...
One of the most promising use cases of magnetic hyperthermia, is the use of magnetic nanoparticles (MNPs) for cancer therapy. In this treatment, MNPs are immersed into tumours and by heating with external magnetic fields, typically 100-900 kHz, destroy cancer cells. Since it is a clinical application the optimization of field parameters and in turn, the heating power, is crucial to maintain...
Nanoparticles are nowadays widely used in biology and have quickly emerged as essential to modern medicine. When nanomaterials come into contact with biological membrane, their interaction with biomacromolacules and biological barriers will determine their bioactivity, biological fate and cytotoxicity. It goes without saying that understanding the interaction between nanomaterial and...
Hydrogen as energy carrier is one of the hot topics aimed at stopping global warming. Hydrogen storage is one of its challenges. The problems of storage in high-pressure vessels and liquefaction (physical methods) are, firstly, high energy requirements and, secondly, hydrogen leaks through vessel walls via diffusion. When stored chemically, $\mathrm{H_2}$ is produced only on demand. This...
Since their inception, neutron scattering methods have significantly contributed to many advancements in solid state research. This is especially true for the study of magnetic materials, where neutrons provide a uniquely qualified probe to investigate magnetism on the microscopic scale. This talk aims to elucidate the relation between the magnetic properties of a sample and the observable...
The symmetry of multiple magnetic phenomena, e.g. ferromagnetism, collinear ordering, spin reorientation, or canted antiferromagnetism, do not depend on the atomic positions. They depend only on the set of directions of magnetic moments, which we will call magnetic mode. We will present the complete classification of magnetic modes [1] based on the magnetic point groups used in two contexts:...
The science community faces a challenging situation to maintain sustainable research with neutron methods at the moment. While neutron scattering is an indispensable microscopic probe for the investigations of magnetic order and spin excitations, there are complementary techniques at the large-scale facilities that are also suitable for magnetism research, such as element-specific magnetic...
The thermal beamport SR8 at the research neutron source Heinz Maier-Leibnitz in Garching will be optimized to allow the simultaneous operation of three independent monochromatic powder diffractometers. SPODI will continue to be one of the world-leading high-resolution powder diffractometers. FIREPOD will be a dedicated high throughput instrument, well suited for a broad range of fast...
Polysaccharides are the major natural originated components finding extensive investigation and utilization in diverse fields including the nutritional manufacturing sector. Due to their advantageous properties such as safety, stability, biocompatibility, biodegradability and nontoxicity, polysaccharide-based complex systems have a significant potential in the fields of cosmetics,...
Microfluidic flows using hyperbolic contractions and capillary break-up extensional rheometery (CaBER) have emerged as key techniques to characterize polymer solutions experiencing uniaxial extensional flow [1,2]. In this work, two approaches are presented to explore the microstructural evolution during extensional flows and relate those features in situ to the macroscopic properties exhibited...
Magnets based on high temperature superconductor (HTS) provides an extreme sample environment to provide a magnetic field to detect weaker, often diffuse signals of (quantum) disordered systems. Therefore, studying HTS magnet behavior and quench properties is an essential aspect of neutron research instrumentation. In this project, we are using metal -insulation co-winding technology, where...
The single crystal diffractometer POLI is dedicated to diffraction using polarized neutrons and can additionally host bulky sample environments. Currently, three standard setups are implemented on POLI: zero-field spherical neutron polarimetry, flipping ratio method with high magnetic fields and non-polarized diffraction under various special conditions. Here we reported our recently...
Neutron and X-ray scattering experiments are powerful techniques to investigate any material at the atomic to mesoscopic level. They give us structural and dynamic information. However, it is not possible to extract the relative position, shape, and velocity of the scatterers directly from the scattering data due to the phase problem. One possibility to circumvent this problem is to simulate...
The neutron single crystal diffractometer HEiDi uses the hot source of FRM II to offer high flux down to short wavelengths. Its large $q$ range and flexibility concerning experiments between 2.5 K and 1300 K make it a versatile tool for detailed studies on structures for many topics in physics, chemistry and mineralogy.
In two consecutive BMBF-funded projects from 2016 to 2022 (05K16PA3,...
High voltage spinel LNMO is one of the most promising next-generation cobalt-free cathode materials for Li-ion batteries. Besides the typical compositional range of LixNi0.5Mn1.5O4 (0 < x < 1) in the voltage window 4.90 to 3.00 V, additional Li can be introduced into the structure in an extended voltage range to 1.50 V. Theoretically, this leads to significant increase of the specific energy...
Materials based on semi-crystalline polymers are used in different fields of applications, from high temperature to plastics, elastomers and fibers, from biomedicine to aerospace, from oil industry to fuel cells. Such materials exhibit a phase separation in crystalline and amorphous regions. The crystalline domains are characterised by a complex morphology spanning a broad length scale from Å...
By utilizing time-of-flight neutron reflectometry (ToF-NR) under different relative humidity, we demonstrate that polymer brushes constituted by hydrophilic cyclic macromolecules exhibit more compact conformation with lower roughness compared to linear brush analogues, due to the absence of dangling chain ends extending at the interface. [1] In addition, due to increased interchain steric...
The stability of food emulsions depends -beside other effects- on a complex interplay between proteins, phospholipids, oil and water. Preparing milk-based and sustainable plant-based emulsions requires good knowledge in interfacial and emulsion stabilization mechanisms, affected by the emulsion composition. To understand these mechanisms in detail different length scales from interatomic to...
Elemental analysis with neutrons is based on the excitation of atomic nucleus inducing penetrant gamma rays, thus enabling the non-destructive bulk analysis of samples. With prompt gamma activation analysis (PGAA), all elements can be detected: the higher their neutron capture cross section, the stronger their signal in the gamma spectrum. It is unique in the determination of light elements...
The newly discovered kagome superconductors AV3Sb5 (A=K, Rb or Cs), in which non-trivial band topology, charge-density wave (CDW), and superconductivity are intertwined, have attracted tremendous interests. Despite extensive recent investigations via X-ray diffraction and other complementary local probe techniques such as STM, NMR and muon spectroscopy etc., it remains a major challenge to...
Over the past years, NECTAR has received multiple upgrades, including a new translation/rail system, a scintillator changer, scraper for fast neutrons, and event mode imaging capabilities. The upgrades improve existing capabilities but also enable more advanced new techniques, such as multimodal imaging and event-based neutron imaging. Here, we propose to discuss the current status, as well as...
The second largest cause of measurement time loss at NEPOMUC is the time spent to optimize the positron beam to the specification required by the user; the speed of this optimization process is primarily determined by the available detection techniques. As modern positron spectroscopy requires beams of ever higher intensity and focus, it is paramount for our complex to develop and adopt faster...
ODIN is the ESS state-of-the-art multipurpose neutron imaging instrument. Using wavelength-resolved imaging with tunable medium to high wavelength resolution, ODIN will provide significantly increased chemical and structural sensitivity compared to other traditional neutron imaging instruments, with fixed (or absent) wavelength resolutions. ODIN will view both the cold and the thermal...
