TY  - JOUR
A1  - Porȩba, Tomasz
A1  - Racioppi, Stefano
A1  - Garbarino, Gaston
A1  - Morgenroth, Wolfgang
A1  - Mezouar, Mohamed
T1  - Investigating the structural symmetrization of CsI3 at high pressures through combined X-ray diffraction experiments and theoretical analysis
JF  - Inorganic chemistry
N2  - ABSTRACT: Structural evolution of cesium triiodide at high pressures has been revealed by synchrotron single-crystal X-ray diffraction. Cesium triiodide undergoes a first-order phase transition above 1.24(3) GPa from an orthorhombic to a trigonal system. This transition is coupled with severe reorganization of the polyiodide network from a layered to three-dimensional architecture. Quantum chemical calculations show that even though the two polymorphic phases are nearly isoenergetic under ambient conditions, the PV term is decisive in stabilizing the trigonal polymorph above the transition point. Phonon calculations using a non-local correlation functional that accounts for dispersion interactions confirm that this polymorph is dynamically unstable under ambient conditions. The high-pressure behavior of crystalline CsI3 can be correlated with other alkali metal trihalides, which undergo a similar sequence of structural changes upon load.
Y1  - 2022
U6  - https://doi.org/10.1021/acs.inorgchem.2c01690
SN  - 0020-1669
SN  - 1520-510X
VL  - 61
IS  - 28
SP  - 10977
EP  - 10985
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Rosa, Angelika D.
A1  - Dewaele, Agnès
A1  - Garbarino, Gaston
A1  - Svitlyk, Volodymyr
A1  - Morard, Guillaume
A1  - De Angelis, Filippo
A1  - Krstulovic, Marija
A1  - Briggs, Richard
A1  - Irifune, Tetsuo
A1  - Mathon, Olivier
A1  - Bouhifd, Mohamed Ali
T1  - Martensitic fcc-hcp transformation pathway in solid krypton and xenon and its effect on their equations of state
JF  - Physical review / publ. by The American Institute of Physics. B
N2  - The martensitic transformation is a fundamental physical phenomenon at the origin of important industrial applications. However, the underlying microscopic mechanism, which is of critical importance to explain the outstanding mechanical properties of martensitic materials, is still not fully understood. This is because for most martensitic materials the transformation is a fast process that makes in situ studies extremely challenging. Noble solids krypton and xenon undergo a progressive pressure-induced face-centered cubic (fcc) to hexagonal close-packed (hcp) martensitic transition with a very wide coexistence domain. Here, we took advantage of this unique feature to study the detailed transformation progress at the atomic level by employing in situ x-ray diffraction and absorption spectroscopy. We evidenced a four-stage pathway and suggest that the lattice mismatch between the fcc and hcp forms plays a key role in the generation of strain. We also determined precisely the effect of the transformation on the compression behavior of these materials.
Y1  - 2022
U6  - https://doi.org/10.1103/PhysRevB.105.144103
SN  - 2469-9950
SN  - 2469-9969
VL  - 105
IS  - 14
PB  - American Physical Society
CY  - College Park
ER  -