First-principles and Monte Carlo combinational study on Zn1−xCoxO diluted magnetic semiconductor

The electronic structures and magnetic properties of Zn1−xCoxO (x=5.55%,8.33%,12.5%x=5.55%,8.33%,12.5%) are studied using first-principles calculations in combination with Monte Carlo (MC) simulation. The combinational method makes possible a complete simulation from the microscopic magnetic interaction to macroscopic magnetic behavior. The calculated results from first principles indicate that the ferromagnetic ground state is stabilized by a half-metallic electronic structure which originates from the strong hybridization between Co 3d electrons and O 2p electrons. With the magnetic coupling strengths obtained from first-principles calculations, the MC simulation predicts the ferromagnetism of Zn1−xCoxO (x=5.55%,8.33%,12.5%x=5.55%,8.33%,12.5%) with Tc=220,360,530K, which is consistent with the experimental facts.