Magnetic properties of Mn-doped GaN with defects:ab-initio calculations

作     者：E.Salmani A.Benyoussef H.Ez-Zahraouy E.H.Saidi 

作者机构：LMPHEDepartement de PhysiqueFacult'e des SciencesUniversit'e Mohammed V-AgdalRabatMorocco LPHEDepartement de PhysiqueFacult'e des SciencesUniversit'e Mohammed V-AgdalRabatMorocco 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2011年第20卷第8期

页      面：297-303页

核心收录：

学科分类：080903[工学-微电子学与固体电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

主　　题：diluted magnetic semiconductor GaN:Mn defects ab-initio magnetic properties 

摘      要：According to first-principles density functional calculations, we have investigated the magnetic properties of Mn- doped GaN with defects, Ga1-x-yVGxMny N1-z-tVNzOt with Mn substituted at Ga sites, nitrogen vacancies VN, gallium vacancies VG and oxygen substituted at nitrogen sites. The magnetic interaction in Mn-doped GaN favours the ferromagnetic coupling via the double exchange mechanism. The ground state is found to be well described by a model based on a Mn3＋-d5 in a high spin state coupled via a double exchange to a partially delocalized hole accommodated in the 2p states of neighbouring nitrogen ions. The effect of defects on ferromagnetic coupling is investigated. It is found that in the presence of donor defects, such as oxygen substituted at nitrogen sites, nitrogen vacancy antiferromagnetic interactions appear, while in the case of Ga vacancies, the interactions remain ferromagnetic; in the case of acceptor defects like Mg and Zn codoping, ferromagnetism is stabilized. The formation energies of these defects are computed. Furthermore, the half-metallic behaviours appear in some studied compounds.