Interfaces between MgA1₂O₄ Spinel Layers and Oxide Substrates

Abstract

Interfaces including A1203 (sapphire, S) and MgAlzOa (spinel, SP) have been object of some investigations, in particular in topotaxial systems. However, details concerning the interfacial structure have rarely been reported. In our study thin films of MgA1204 spinel on basal lane sapphire were prepared by chemical solution deposition (CSD). A precursor solution, containing Al(N03)3 and Mg(N03)2 is deposited on the substrates. Optimum conditions for heteroepitaxial growth are achieved by a 4h heat treatment at 1250°C. X-ray and electron diffraction prove epitactixial growth of the spinel phase on the sapphire substrate. The orientation relationship is