Influence of Stress on Electronic and Optical Properties of Rocksalt and Wurtzite MgO-ZnO Nanocomposites with Varying Concentrations of Magnesium and Zinc

The structural, electronic and optical properties of stressed MgO-ZnO nanocomposite alloys with concentrations of Zn and Mg varying from 0.125 to 0.875 were studied using ab initio simulations. Two crystal structures are considered for the initial MgO-ZnO alloys: the rocksalt Mg1-xZnxO and wurtzite Zn1-xMgxO phases. For rocksalt Mg1-xZnxO, the optimized structures are stable at pressures below 10 GPa. The larger the Mg concentration and pressure, the wider the E g of the rocksalt phase. In contrast, the optimal geometries of wurtzite Zn1-xMgxO reveal a diversity of possibilities, including rocksalt, wurtzite and mixed phases. These effects lead to the fact that the optical properties of wurtzite Zn1-xMgxO not only demonstrate the properties of the wurtzite phase but also indicate the optical features of the rocksalt phase. In addition, mixed phases of Zn1-xMgxO simultaneously provide the characteristics of both wurtzite and rocksalt phases with the same structures in different dielectric matrices.