Lithium disorder in the vicinity of the superionic phase transition in monoclinic and rhombohedral Li3In2(PO4)3

Autor: V. V. Kravchenko, S. E. Sigaryov
Rok vydání: 1994
Předmět:
Zdroj: Journal of Materials Science. 29:6004-6010
ISSN: 1573-4803
0022-2461
DOI: 10.1007/bf00366886
Popis: Rhombohedral and monoclinic modifications of the Li3In2(PO4)3 compound have been studied by X-ray diffraction, infrared (i.r.) analysis, Raman light scattering, differential thermal analysis (DTA), differential scanning calorimetry (DSC) and impedance spectroscopy, in a wide temperature range of 290–600 K. Analysis of the data allows the suggestion that the superionic phase transition, observed in these materials in the temperature interval 370–385 K, belongs to Faraday type phase transformations. PO4 tetrahedra, which are a partition of the (In2P3O12) 300 3− rigid skeleton, have been found deformed. This seems to be due to an ordered lithium ion-vacancy distribution in the low temperature, non-superionic, polymorphs. With increasing temperature these deformations disappear. This disappearance can be caused by a decrease of the correlation length of the lithium ion-vacancy order.
Databáze: OpenAIRE