First-principles LDA+U study of magnetism in CuxIn1−xN

Abstract

We have carried out First-principles spin-polarized calculations in order to study the electronic structure and magnetism in Cu-doped InN using the LDA+U and LDA formalisms within density functional theory (DFT) with a plane-wave ultrasoft pseudopotential scheme. We found a stable ferromagnetic state in Cu0.0625In0.9375N with a total magnetization of 1.98μB per supercell, indicating Cu orders ferromagnetically in InN. The results indicate that the ferromagnetic ground state originates from the hybridized Cu(3d)–N(2p)–In(5p)–N(2p) chain formed through p–d coupling. Formation energy and ground state calculations have been performed for ferromagnetic and antiferromagnetic states of CuxIn1−xN (x=0,0625 and 0,125) by LDA+U and LDA formalisms. A weak ferromagnetic behavior for CuxIn1−xN (x=0,125) was found. The results predicted an AFM ground state for cases where the Cu atoms are closer. For longer Cu–Cu distances a stable FM ground state was found. This ferromagnetic behavior in CuxIn1−xN (x=0,125) could be tuned with In or N vacancies.