过渡金属掺杂ZnO纳米线结构、电子性质和磁性质

Structures, electronic and magnetic properties of transition metal doped ZnO nanowires

摘要:

本文采用密度泛函理论系统的研究了过渡金属原子Co和Ni单掺杂和双掺杂ZnO纳米线的结构、电子性质和磁性质. 所有掺杂纳米线的束缚能都为负值，表明掺杂过程是放热的. Co原子趋于占据纳米线中间位置，而Ni原子趋于占据纳米线表面位置. 所有掺杂纳米线能隙都小于纯纳米线能隙，并显示出直接带隙半导体特性. 纳米线的总磁矩主要来源于磁性原子的贡献. Co掺杂纳米线出现了铁磁和反铁磁两种耦合状态；而Ni掺杂纳米线出现了铁磁、反铁磁和顺磁三种耦合状态.

Abstract:

The gerometric structures, electronic and magnetic properties of the Co and Ni single doped and double doped ZnO nanowires are systematically studied by using density functional theory. It is found that the binding energies of the doped nanowires are negative, which indicates that the doping process is an exothermic reaction. The Co atom tends to occupy the intermediate position, while the Ni atom tends to occupy the surface position. All doped nanowires show direct band gap semiconductor behavior with the narrow energy gap. The magnetic moments of the nanowires mainly originate from the 3d orbitals of magnetic atoms. Two ferromagnetic and antiferromagnetic coupling states appear in the Co-doped nanowires, while three ferromagnetic, antiferromagnetic and paramagnetic coupling states appear in the Ni-doped nanowires.