A Raman study of cation-disorder transition temperature of natural MgAl2O4 spinel

Abstract

We have measured Raman spectra of samples of natural MgAl2O 4 spinel before and after annealing at different temperatures and quenching. The appearance of 727cm-1 mode in the samples annealed at 800°C or higher is believed to be due to the cation-disorder of spinel. The full-width-at-the-half-maximum (FWHM) values of the 410cm-1 mode as a function of the annealing temperature clearly shows an abrupt increase at the temperature between 700 and 750°C as the annealing temperature increases. Thus, we find the annealing temperature at which the cation-disorder occurred in the natural MgAl2O4 spinel to be between 700 and 750°C. © 2004 Elsevier B.V. All rights reserved.