Raman study of alloy potential fluctuations in MgxZn1-xO nanopowders

Abstract

The blueshift of near-band-edge emission and excitonic absorption indicate that Zn2+ ions are successfully substituted by Mg2+ ions in MgxZn1-xO nanopowders for 0 <= x <= 0.14. The changes in Raman spectral linewidth and the asymmetry of the E-2 ( high) mode for various Mg contents can be well described by a modified spatial correlation model that considers the grain size distribution. With increasing Mg concentration, the alloy potential fluctuations lead to a decrease in the grain size, which is induced by the surplus Mg2+ that could form MgO clusters surrounding the crystalline MgZnO.