Effects of the crystal structure on the ferromagnetic correlations in   ZnO with magnetic impurities
  We study the ferromagnetism in the compound (Zn,Mn)O within the Haldane-Anderson impurity model by using the quantum Monte Carlo technique and the tight-binding approximation for determining the host band-structure and the impurity-host hybridization. This computational approach allows us to determine how the host crystal structure influences the impurity bound state, which plays an important role in the development of the ferromagnetic (FM) correlations between the impurities. We find that the FM correlations are strongly influenced by the crystal structure. In particular, in p-type (Zn,Mn)O, we observe the development of FM correlations with an extended range at low temperatures for wurtzite and zincblende crystal structures. However, for the rocksalt structure no FM correlations are observed between the impurities. In addition, in n-type ZnO with magnetic impurities, the impurity bound state and FM correlations are not found. 
Bo Gu, Nejat Bulut, and Sadamichi Maekawa