Microstructure and residual stress in γ-LiAlO2 layer fabricated by vapor transport equilibration on (1 1 2¯ 0) sapphire

Abstract

γ-LiAlO2 layers have been fabricated by vapor transport equilibration (VTE) technique on (112¯0) sapphire substrate. Microstructure of γ-LiAlO2 layers is characterized by X-ray diffraction as functions of VTE treatment temperature and sapphire surface roughness, it has been found that the LiAlO2 layers show a (200) preferred orientation. The effects of the VTE treatment temperature and sapphire surface roughness on the residual stress have been studied. The results show that residual stress in γ-LiAlO2 layers varies from tension to compression with increasing VTE treatment temperature , but the thermal stress is compressive; the values of residual stress in γ-LiAlO2 layers increase with the sapphire surface roughness.