Al和氧空位对ZnO:Co稀磁半导体磁性质的影响

Effect of Al and oxygen vacancy defect on the magnetic properties of Co-doped ZnO

利用基于密度泛函理论的第一性原理计算方法,研究了Al共掺杂和氧空位缺陷对Co掺杂ZnO磁性质的影响,发现Al原子共掺杂引入的自由电子载流子会稳定体系的反铁磁性从而减弱Co原子间的铁磁性交换,而氧空位缺陷束缚的电子载流子对提高体系的铁磁性具有积极的作用.氧空位引入的电子载流子部分转移到Co原子和近邻Zn原子,形成以电子载流子为媒介的Co原子间的耦合作用,稳定体系的铁磁态,增强Co原子间的交换耦合作用.

The influence of A1 and oxygen vacancy on the magnetism of Co - doped ZnO has been in- vestigated by the first- principles calculations based on density functional theory （DFT）. It is found that the doping A1 into ZnO：Co would favor antiferromagntism and weaken the ferromagnetic exchange interaction between Co atoms. Carrier doping can enhance the ferromagnetism only in the presence of oxygen vacancy. The doping electrons introduced by oxygen vacancy might be available for carrier me- diation and can strengthen the ferromagnetic exchange interaction between Co atoms.