Theoretical study of phase separation in Cd1−xZnxO alloys

First-principles study of the ground-state properties and the stability of Cd1−xZnxO solid solutions are presented using the full-potential linearized, augmented plane-wave (FP-LAPW) method in combination with the local density approximation (LDA). It is found that the structural parameters, i.e. lattice constants and bulk moduli strongly deviate from the linear function of the composition xx. The equation of state of the alloys is determined and an increasing compressibility function of composition is found. The formation energy is viewed as an energetic balance between pure structural constraints and quantum chemical effects. Our calculations yield the prediction of phase separation over the whole range of concentration. This trend was explained to have a structural nature caused by the high lattice mismatch. Also, the thermodynamic stability of the alloys has been investigated.