High Curie temperatures in (Ga,Mn)N from Mn clustering

الأصل · EN

The effect of microscopic Mn cluster distribution on the Curie temperature (Tc) is studied using density-functional calculations. We find that the calculated Tc depends crucially on the microscopic cluster distribution, which can explain the abnormally large variations in experimental Tc values from a few K to well above room temperature. The partially dimerized Mn₂-Mn₁ distribution is found to give the highest Tc > 500 K, and in general, the presence of the Mn₂ dimer has a tendency to enhance Tc. The lowest Tc values close to zero are obtained for the Mn₄-Mn₁ and Mn₄-Mn₃ distributions.