Evolution towards centrosymmetry of the nonlinear-optical materialRbTiOPO4in the temperature range 293–973 K: Alkaline displacements and titanyl deformations

Autor:	Bertrand Ménaert, Claude Lecomte, G. Marnier, P. Delarue, M. Jannin
Rok vydání:	1998
Předmět:	Materials science business.industry Anharmonicity chemistry.chemical_element Crystal structure Atmospheric temperature range Centrosymmetry Rubidium Ion Crystal Optics chemistry Atomic physics business Intensity (heat transfer)
Zdroj:	Physical Review B. 58:5287-5295
ISSN:	1095-3795 0163-1829
Popis:	The crystal structure of rubidium titanyl phosphate, ${\mathrm{RbTiOPO}}_{4}$ (space group ${\mathrm{Pna}2}_{1}$), has been refined at room temperature, and at 473, 673, 873, and 973 K, by using single-crystal x-ray-diffraction techniques. The data show a large anharmonic motion of the rubidium ions increasing with temperature. To describe the importance of this motion in the phase-transition procedure and in the ionic conductivity phenomenon, two models are developed. The study of the deviation to the centrosymmetric structure (space group Pnan) shows that the change towards centrosymmetry of the titanyl groups correlates directly with the observed variation of the second-harmonic generating intensity ${I}_{2\ensuremath{\omega}}$ of the ${\mathrm{RbTiOPO}}_{4}$ crystal versus temperature.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::86c904df9683169749322e087a40c3f7 https://doi.org/10.1103/physrevb.58.5287 Zobrazit plný text záznamu