Conveners
Structure Research: Structure Research I
- Martin Meven (RWTH Aachen University, Institute of Crystallography - Outstation at MLZ)
- Anatoliy Senyshyn
Structure Research: Structure Research II
- Anatoliy Senyshyn
- Martin Meven (RWTH Aachen University, Institute of Crystallography - Outstation at MLZ)
Structure Research: Structure Research III
- Martin Meven (RWTH Aachen University, Institute of Crystallography - Outstation at MLZ)
- Anatoliy Senyshyn
Acid-base catalysis, which involves one or more proton transfer reactions, is a chemical mechanism commonly employed by many enzymes. The molecular basis for catalysis is often derived from structures determined at the optimal pH for enzyme activity. However, direct observation of protons from experimental structures is quite difficult; thus, a complete mechanistic description for most enzymes...
The availability of large high-quality single crystals is an important rerequisite for many studies in solid-state research. The optical floating-zone technique is an elegant method to grow such crystals, offering potential to prepare samples that may be hardly accessible with other techniques. As elaborated in this presentation, examples include single crystals with intentional compositional...
The advent of solid-state batteries has spawned a recent increase in interest in lithium conducting solid electrolytes, especially in the lithium thiophosphates. However, many open questions remain when trying to optimize electrolytes and understand solid state battery chemistries.
In this presentation, we will show how an understanding of the structure-transport properties of the lithium...
We investigated why commercial Li7La3Zr2O12 (LLZO) with Nb- and Ta substitution shows very low mobility on a local scale, as observed with temperature-dependent NMR techniques, compared to Al and W substituted samples, although impedance spectroscopy on sintered pellets suggests something else: conductivity values do not show a strong dependence on the type of substituting cation. We observed...
In this presentation I will show examples of using in situ powder diffraction to simultaneously access the structure and adsorption properties of a small pore crystalline solid. (Quasi)-equilibrium isotherms and isobars can be built directly from sequential Rietveld refinements, both on adsorption and desorption, thus addressing the hysteresis and kinetics of gas adsorption/desorption....
Since the discovery of charge disproportionation in the FeO$_2$ square-lattice compound Sr$_3$Fe$_2$O$_7$ by Mössbauer spectroscopy more than fifty years ago, the spatial ordering pattern of the disproportionated charges has remained “hidden” to conventional diffraction probes, despite numerous x-ray and neutron scattering studies. We have used neutron Larmor diffraction and Fe $K$-edge...
The structural complexities in the Na0.5Bi0.5TiO3 (NBT)-based Pb-free piezoelectrics pose significant challenge regarding understanding of the structure-property correlation. While the critical compositions exhibiting maximum weak-signal piezoelectric response is generally associated to an inter-ferroelectric instability, a combined neutron diffraction and piezoelectric study on three...
Multiferroic Ba$_{2}$CoGe$_{2}$O$_{7}$ belongs to the square lattice Heisenberg antiferromagnets (SLHAF), which exhibit rich quantum phase diagrams of exchange interactions, Dzyaloshinskii-Moriya interactions with the external magnetic or electric fields, but the correlation between single-ion anisotropy and the magnetic field has remain hitherto unexplored through experimental findings in...
A custom-made, multilayered Li-ion battery pouch cell was investigated using operando neutron powder diffraction (NPD) and spatially resolved powder X-ray diffraction (SR-PXRD) with the aim of comparing the information obtained from the two complementary techniques. The work focused on the anode and cathode lithiation as obtained from the LiC6/LiC12 weight ratio and the NMC111 c/a-ratio,...
Large single crystals of garnet-type Li6La3ZrTaO12 (LLZTO) and Ga-doped Li7La3Ze2O12 (Ga-LLZO) were grown by the Czochralski method and analysed using neutron diffraction between 2.5 and 873 K in order to fully characterize the Li-atom distribution, and possible Li ion mobility in this class of potential candidates for solid state electrolyte battery material. The LLZTO retains its cubic...
