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Crystallography 2018 Structural Chemistry & Crystallography Communication
ISSN: 2470-9905 Page 25
June 04-05, 2018
London, UK
3rd Edition of International Conference on
Advanced Spectroscopy,
Crystallography and Applications
in Modern Chemistry
Adiamond anvil cell (DAC) is the most versatile tool to study
structures and physical properties of (non-)crystalline
materials at high pressures. The range of experimental
techniques in a DAC is very broad: synchrotron and X-ray
diffraction, inelastic X-ray scattering, optical and vibrational
spectroscopies, etc. However, the main disadvantage of
the DAC is a limited sample volume that is available in the
sample chamber. Owing to the development of modern two-
dimensional detectors and radiation sources, high-pressure
single-crystal X-ray diffraction in the DAC using laboratory
and synchrotron facilities can now be performed on complex
crystal structures that are twinned or modulated. On the other
hand, there are hardly any single-crystal neutron diffraction
studies in the DAC that would present complete structural
refinements. Up to now, even at the most advanced neutron
facilities it is difficult to routinely study crystals with volumes
below 1 mm3 due to the low flux of the neutron beams. The
requirement for large samples hinders a joint use of X-ray
and neutron single-crystals diffraction upon compression.
The combination of both techniques is highly advantageous
for detailed studies on crystalline compounds, as neutron
diffraction plays a crucial role in those cases where X-ray
diffraction fails to provide information on, for instance,
magnetic order or compounds containing light elements.
Recently, we have started to explore the feasibility of neutron
measurements in the DAC on the single-crystal diffractometer
HEIDI at the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching
(Germany) that offers the benefit of various short wavelengths
with high fluxes. We have now developed optimized DACs for
measurements on crystals smaller than 0.1 mm3 at room and
low temperatures in the transmission and radial (panoramic)
neutron scattering geometries. Some of these DACs could well
be used for combined X-ray and neutron investigations.
Recent Publications
1. Friese, K., Grzechnik, A., Posse, J.M., Petricek, V.
(2013) - Refinement of high-pressure single-crystal
diffraction data using Jana2006 – High Pressure
Research, 33, 196.
2. Friese, K., Grzechnik, A. (2014) – Twinning and
pseudosymmetry under high pressure – Z.
Kristallogr.229, 158.
3. Grzechnik, A., Ueda, Y., Yamauchi, T., Hanfland, M.,
Hering, P., Potapkin, V., Friese, K. (2015) - Structural
stability of the Wadsley-type bronzes -Ag0.33V2O5
and -Li0.33V2O5 on compression: a break-down of
the two-leg ladder system in the non-superconducting
high-pressure phase of -Li0.33V2O5 – Phys. Rev. B
91, 174113.
4. Grzechnik, A., Yeon, J., zur Loye, H.-C., Friese, K.
(2016) - High-pressure behaviour of Cs2V3O8 – J.
Solid State Chem. 238, 252-258.
5. Friese, K., Khaidukov, N., Grzechnik, A. (2016) -
Twinned CsLn2F7 compounds (Ln = Nd, Gd, Tb, Er,
Yb): the role of a highly symmetrical cation lattice with
an arrangement analogous to the Laves phase MgZn2
– Z. Kristallogr., 231, 631-639.
HIGH-PRESSURE CRYSTALLOGRAPHIC STUDIES IN DIAMOND ANVIL CELLS
USING X-RAYS AND NEUTRONS
Andrzej Grzechnik
RWTH Aachen University, Germany
Andrzej Grzechnik, Struct Chem Crystallogr Commun 2018, Volume 4
DOI: 10.21767/2470-9905-C1-005