Structural aspects of displacive transformations: what can optical microscopy contribute? Dehydration of Sm₂(C₂O₄)₃·10H₂O as a case study

Abstract

For martensitic transformations the macroscopic crystal strain is directly related to the corresponding structural rearrangement at the microscopic level. In situ optical microscopy observations of the interface migration and the change in crystal shape during a displacive single crystal to single crystal transformation can contribute significantly to understanding the mechanism of the process at the atomic scale. This is illustrated for the dehydration of samarium oxalate decahydrate in a study combining optical microscopy and single-crystal X-ray diffraction.

Anisotropic lattice softening near the structural phase transition in the thermosalient crystal 1,2,4,5-tetrabromobenzene

“…Although the crystal structures of the β-and γphases have been refined at single temperature points before and after the phase transition 7,9,10 , the structure has not been monitored at temperatures immediately up to and following the phase transition. This structural data could offer unambiguous determination of anisotropic lattice strain, and the possible existence of any intermediate phases involved in the thermosalient phenomenon of TBB 16,17 . While previous work has reported variable-temperature powder X-ray diffraction data, 5 it was not sufficient to provide this detailed information.…”

A large anisotropic plasticity of L-leucinium hydrogen maleate preserved at cryogenic temperatures

“…Mechanical properties of molecular crystals have long been known to have a pronounced effect on their transformations, including crystallization (Shtukenberg et al, 2014(Shtukenberg et al, , 2017Crist & Schultz, 2016;Li et al, 2018), polymorphic transformations (Mnyukh, 1963(Mnyukh, , 1979Kitaigorodskiy et al, 1965;Williams, 1973;Chupakhin et al, 1987;Herbstein, 2006;Matvienko et al, 2017;Minami et al, 2018;Zakharov et al, 2018) and solid-state chemical reactions (McBride, 1983;McBride et al, 1986;Luty & Fouret, 1989;Boldyrev, 1996;Boldyreva & Boldyrev, 1999;Luty et al, 2002;Larsen & Boydston, 2013;Nath et al, 2014Nath et al, , 2015Naumov et al, 2015;Commins et al, 2016;Boldyrev, 2018;Chizhik, Matvienko & Sidelnikov, 2018;Hao et al, 2018;Rai et al, 2018;Zakharov & Boldyreva, 2019). In the last decade, increasing attention has been paid to the mechanical properties of organic crystals but not necessarily in relation to their response to light or temperature variation.…”

Thermal reactions involving solids: a personal view of selected features of decompositions, thermal analysis and heterogeneous catalysis

“…During his productive years, he led the Group for the Reactivity of Solids, Novosibirsk, Russia, between 1978 and 2013, before being succeeded by his daughter, Elena V. Boldyreva from 2013 to 2017. The output from this group still continues, including the very recent publications [14][15][16][17].…”