非金属N和过渡金属(Mo,Ru,Rh,Pd)掺杂SnO_(2)磁性的第一性原理研究

First principles study on magnetic properties of SnO_(2) co-doped with nonmetal N and transition metals(Mo,Ru,Rh,Pd)

本文基于第一性原理方法,对非金属元素(N)与过渡金属元素(Mo,Ru,Rh,Pd)掺杂SnO_(2)的电子结构和磁学性质进行计算分析.结果表明:形成能与过渡金属原子半径密切相关,随着过渡金属原子半径的增加,形成能在降低,其中N-Mo掺杂体系形成能最低,故该体系最容易掺杂形成;能带结构分析表明,由于掺杂体系自旋向上/向下杂质能级的数量和分布均不对称,掺杂体系均有磁性产生;进一步探究态密度可知,体系产生磁性的原因是过渡金属原子和N原子之间产生p-d轨道杂化,最外层电子轨道上的空位及单电子相互耦合所导致.结果表明,由于掺杂原子的引入,SnO_(2)体系产生磁性,并且掺杂体系呈现亚铁磁性,其中N-Rh掺杂体系的磁性最好,其磁矩为1.88μB,有望成为良好的稀磁半导体材料.

In this paper,the electronicstructures and magnetic properties of SnO_(2) doped with non-metallic elements(N)and transition metal elements(Mo,Ru,Rh,Pd)are calculated and analyzed based on the first principles approach.The results show that:the formation energy is closely related to the transition metal atomic radius,with the increase of the transition metal atomic radius,the formation energy is decreasing,where the N-Mo doping system has the lowest formation energy,so the system is the easiest to doping formation.Energy band structure analysis shows that due to the number and distribution of spin up/spin down impurity energy levels of the doping system are asymmetric,the doping systems are magnetic generation.Further exploration of the density of states shows that the magnetic properties of the doped system are due to the p-d orbital hybridisation between the transition metal atoms and the N atoms,the vacancies in the outermost electron orbitals and the single electron coupling.The results show that the SnO_(2) system is magnetic due to the introduction of doping atoms,and the doped system exhibits subferromagnetic properties,with the best magnetic moment of 1.88μB for the N-Rh doped system,which is expected to be a good dilute magnetic semiconductor material.