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...
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...
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...
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...
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,...
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...
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...
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...
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...
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...
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...