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An in situ Raman spectroscopic study of pressure induced dissociation of spinel NiCr2O4

An in situ Raman spectroscopic study of pressure induced dissociation of spinel NiCr2O4

Authors :
Hugh St. C. O'Neill
Surendra K. Saxena
Zhongwu Wang
Peter Lazor
Source :
Journal of Physics and Chemistry of Solids. 64:425-431
Publication Year :
2003
Publisher :
Elsevier BV, 2003.

Abstract

An in situ Raman spectroscopic study was conducted to investigate the pressure induced phase transformation of spinel NiCr 2 O 4 to pressures of 57.1 GPa. Results indicate that NiCr 2 O 4 spinel dissociates to the mixture of Cr 2 O 3 and NiO at 13.1 GPa. Such a dissociation is complete at 25.1 GPa. The coexistence of Cr 2 O 3 and NiO remains up to the peak pressure of 57.1 GPa. Upon release of pressure to 33.3 GPa, the Cr 2 O 3 starts to react with NiO to form the spinel phase, and such a reaction is complete at 18.9 GPa. The recovered spinel phase may exhibit an inverse spinel structure, which differs from the initial normal spinel structure. Combined with the results obtained from other end member chromites, it is suggested that the variation of high-pressure behavior of chromites (ACr 2 O 4 ) significantly depends on the average A–O bond length of the A–O tetrahedron.

Details

ISSN :
00223697
Volume :
64
Database :
OpenAIRE
Journal :
Journal of Physics and Chemistry of Solids
Accession number :
edsair.doi...........51a134c90531aa08901e916fbbd7757c
Full Text :
https://doi.org/10.1016/s0022-3697(02)00328-1