Displacive Character of the Paraelectric–Ferroelectric Phase Transition in K2ZnI4

Autor:	Hiroyuki Mashiyama, Hironobu Kasano
Rok vydání:	2003
Předmět:	Diffraction Phase transition Materials science Condensed matter physics Coincident Tetrahedron General Physics and Astronomy Dielectric Crystal structure Anisotropy Ferroelectricity
Zdroj:	Journal of the Physical Society of Japan. 72:2236-2242
ISSN:	1347-4073 0031-9015
DOI:	10.1143/jpsj.72.2236
Popis:	The crystal structure of K 2 ZnI 4 is refined at 24 temperatures above and below the paraelectric–ferroelectric phase transition temperature by means of X-ray diffraction to reinvestigate the mechanism of the phase transition in more detail. The temperature dependence of the translation of K(1) and K(2) along the b -axis and the rotational angle of the ZnI 4 tetrahedron about the axis nearly parallel to the a -axis is obtained by the structural analyses. It is concluded that the mechanism of this phase transition is not the order–disorder type but the displacive one. The temperature variation of the anisotropic temperature parameter U 22 of K(1), K(2), I(1) and I(2) is coincident with the theoretical prediction for the displacive type phase transition proposed by Fujii and Matsubara [Prog. Theor. Phys. 78 (1987) 177].
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c91d5779778505870431db736ab5a4d6 https://doi.org/10.1143/jpsj.72.2236 Zobrazit plný text záznamu