Local compressibility and substitutional site for the dominant Cr3+-centered octahedron in LaMgAl11O19 crystal

Abstract

The optical spectra and the pressure-induced R-line shift of the dominant Cr(3+) center in LaMgAl(11)O(19) (LMA) crystal are studied. From the studies, the local linear compressibility d ln R/dP approximate to -1.21 x 10(-4) /kbar for the dominant Cr(3+)-centered octahedron in LMA crystal is obtained. By comparing this compressibility with that in ruby (Al(2)O(3):Cr(3+)), we confirm the assignment in the previous paper that the dominant Cr(3+) center is Cr(3+) ion at 4f site of LMA crystal. (C) 2009 Elsevier B.V. All rights reserved.