High pressure Raman spectroscopic study of spinel MgCr2O4

被引：62

作者：

Wang, Z

O'Neill, HSC

Lazor, P

Saxena, SK

机构：

[1] Florida Int Univ, CeSMEC, Miami, FL 33199 USA

[2] Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 2000, Australia

[3] Uppsala Univ, Inst Earth Sci, S-75236 Uppsala, Sweden

来源：

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS | 2002年 / 63卷 / 11期

基金：

美国国家科学基金会;

关键词：

Raman spectroscopy; ceramics; X-ray diffraction;

D O I：

10.1016/S0022-3697(02)00194-4

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

An in situ Raman spectroscopic study was conducted to investigate the pressure induced phase transformation of MgCr2O4 spinel up to pressures of 76.4 GPa. Results indicate that MgCr2O4 spinel undergoes a phase transformation to the CaFe2O4 (or CaTi2O4) structure at 14.2 GPa, and this transition is complete at 30.1 GPa. The coexistence of two phases over a wide range of pressure implies a sluggish transition mechanism. No evidence was observed to support the pressure-induced dissociation of MgCr2O4 at 5.7-18.8 GPa, predicted by the theoretical simulation. This high pressure MgCr2O4 polymorphism remains stable upon release of pressure, but at ambient conditions, it transforms to the spinel phase. (C) 2002 Elsevier Science Ltd. All rights reserved.

引用

页码：2057 / 2061

页数：5

共 22 条

[1] High-pressure decomposition of MCr2O4 spinels (M=Mg, Mn, Zn) by ab initio methods [J].