An x-ray scattering study of Sn.sub.2./sub.P.sub.2./sub.S.sub.6./sub.: absence of incommensurate phase up to 1 GPa

0398275 - FZÚ 2014 RIV GB eng J - Journal Article
Ondrejkovič, Petr - Guennou, Mael - Kempa, Martin - Vysochanskii, Y. - Hlinka, Jiří
An x-ray scattering study of Sn₂P₂S₆: absence of incommensurate phase up to 1 GPa.
Journal of Physics-Condensed Matter. Roč. 25, č. 11 (2013), "115901-1"-"115901-5". ISSN 0953-8984. E-ISSN 1361-648X
R&D Projects: GA ČR GD202/09/H041; GA ČR GAP204/10/0616; GA MŠMT(CZ) LA10010
Institutional support: RVO:68378271
Keywords : X-ray scattering * phase transitions and Curie point * phase diagrams of other materials * incommensurate crystals * dielectric * ferroelectric
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 2.223, year: 2013
http://iopscience.iop.org/0953-8984/25/11/115901

The ferroelectric phase transition in a semiconductor Sn2P2S6 single crystal has been studied by means of high-resolution synchrotron x-ray diffraction in the pressure–temperature range where an incommensurate modulated phase has been anticipated for many years. In contrast with the predictions, the present measurements reveal only a direct ferroelectric–paraelectric phase transition close to T = 100 K, p = 1.1 GPa. In the vicinity of this phase transition, a characteristic critical diffuse scattering was observed, but no satellite peaks could be resolved there. It is concluded that the earlier hypothesis about the presence of an incommensurate phase and associated Lifshitz point in the temperature–pressure phase diagram of Sn2P2S6 is incorrect.
Permanent Link: http://hdl.handle.net/11104/0225761