Phase stability of cubic Mg0.55Zn0.45O thin film studied by continuous thermal annealing method

The phase stability of cubic Mg0.55Zn0.45O thin film grown by metal-organic chemical vapor deposition was studied through continuous thermal annealing. The crystal quality and surface smoothness were greatly improved after a continuous thermal annealing at 750 degrees C. It is attributed to the reducing of interstitial Zn by thermal annealing. However, phase segregation occurred when the sample was annealed at a higher temperature (850 degrees C), which is identified from both x-ray diffraction patterns and optical transmission spectra.