Relative Stabilities of Layered Perovskite and Pyrochlore Structures in Transition Metal-Oxides Containing Trivalent Bismuth

Ramanan, A and Gopalakrishnan, J and Rao, CNR (1985) Relative Stabilities of Layered Perovskite and Pyrochlore Structures in Transition Metal-Oxides Containing Trivalent Bismuth. In: JournaL of Solid State Chemistry, 60 (3). pp. 376-381.

PDF pdf.pdf - Published Version Restricted to Registered users only Download (401kB) | Request a copy

Abstract

In order to investigate the factors determining the relative stabilities of layered perovskite and pyrochlore structures of transition metal oxides containing trivalent bismuth, several ternary and quaternary oxides have been investigated. While d0 cations stabilize the layered perovskite structure, cations containing partially-filled d orbitals (which suppress ferroelectric distortion of MO6 octahedra) seem to favor pyrochlore-related structures. Thus, the vanadium analogue of the layered perovskite Bi4Ti3O12 cannot be prepared; instead the composition consists of a mixture of pyrochlore-type Bi1.33V2O6, Bi2O3, and Bi metal. The distortion of Bi1.33V2O6 to orthorhombic symmetry is probably due to an ordering of anion vacancies in the pyrochlore structure. None of the other pyrochlores investigated, Bi2NbCrO7, Bi2NbFeO7, TlBiM2O7 (M = Nb, Ta), shows evidence for cation ordering in the X-Ray diffraction patterns, as indeed established by structure refinement of TlBiNb2O7.

Item Type:	Journal Article
Publication:	JournaL of Solid State Chemistry
Publisher:	Elsevier Science
Additional Information:	The copyright of this article belongs to Elsevier Science
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	09 Nov 2009 12:57
Last Modified:	19 Sep 2010 05:31
URI:	http://eprints.iisc.ac.in/id/eprint/20124

Actions (login required)

View Item