Nitrogen Vacancy and Magnetic Property in Cu-Doped AlN From First-Principles Calculations

Abstract

The effects on the ferromagnetism of a nitrogen defect in Cu-doped AlN with a Cu concentration of 2.77–8.33% have been investigated by first-principles. For Al $_{0.9723}$ Cu $_{0.0277}$ N, a global magnetic moment of 1.46 $\mu_{\rm B}$ /cell, with a localized magnetic moment of 0.75 $\mu_{\rm B}$ /Cu is found. The formation of Cu-Cu in AlN with the N vacancy $({\rm V}_{\rm N})$ is more energetically favorable than that without the ${\rm V}_{\rm N}$ . Hence, the ${\rm Cu}+{\rm V}_{\rm N}$ state is produced easily. The Cu magnetic moment of Cu-Cu pair becomes very low by the weak 3d-3d spin coupling due to the spin-exchange interaction between Cu-3d and N defect states.