Polymorphism and crystal data of the rare-earth disilicates of type R.E.2Si2O7

doi:10.1016/0022-5088(70)90159-1

Journal of the Less Common Metals

Volume 21, Issue 1, May 1970, Pages 1-14

https://doi.org/10.1016/0022-5088(70)90159-1 Get rights and content

Abstract

The polymorphism of 14 rare-earth disilicate compounds, in the temperature range 900 °–1800 °C, is described by means of single-crystal and powder X-ray data. The thermal stability areas of the 7 observed structure types at normal pressure, and the transition characteristics of the polymorphs are discussed in terms of structural aspects. A description of the rare-earth-oxygen coordination polyhedra and of the [Si₂O₇]⁶⁻ configurations are given approximately by isostructural relations to other disilicate or diphosphate compounds. Complete crystal data and cell dimensions for 30 polymorphic forms, and d-spacings of one representative of each structure type, are provided.

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Polymorphism and crystal data of the rare-earth disilicates of type R.E.2Si2O7

Abstract

J. Inorg. Nucl. Chem.

Mater. Res. Bull.

Mater. Res. Bull.

Mater. Res. Bull.

J. Less-Common Metals

Izv. Akad. Nauk SSSR, Old. Khim. Nauk

Izv. Akad. Nauk SSSR, Otd. Khim. Nauk

Izv. Akad. Nauk SSSR, Otd Khim. Nauk

Izv. Akad. Nauk SSSR, Otd. Khim. Nauk

Izv. Akad. Nauk SSSR, Otd. Khim. Nauk

Izv. Akad. Nauk SSSR, Otd. Khim. Nauk

Izv. Akad. Nauk SSSR, Otd. Khim. Nauk

Izv. Akad. Nauk SSSR, Otd. Khim. Nauk

J. Am. Ceram. Soc.

Dokl. Akad. Nauk SSSR

Naturwiss.

Soviet Phys. Cryst.

Compt. Rend.

Izv. Akad. Nauk SSSR. Otn. Khim. Nauk

Polymorphism and crystal data of the rare-earth disilicates of type R.E.₂Si₂O₇