First Principle Studies On The Properties Of The Bulk, Surface And Interface Of The VSb

The traditional electronic components all used electronic charge as the information carrier, but not considered the other important property-electronic spin. The spin electronic devices based on spin properties (such as spin valves, spin field effect transistors, etc.) needed to achieve high spin polarization of the material injected into the semiconductor. Half-metallic ferromagnet is complete (100%) spin polarization and high Curie temperature. It is the best source of spin-polarized injuction. In the practical spintronics, the existent method of half-metallic materials is film with some thickness. In other word, half-metallic film is really useful in spintronics.In this paper, with the help of the plane-wave pseudopotential method based on the density functional theory, we investigated the electronic structure and the magnetism of the bulk VSb, (001) surface and VSb(001)/GaSb(001) interface in the zinc-blende structure.Our computational results indicate that the spin-up electrons of zencblende VSb are metallic while there is an obvious energy gap around the Fermi level——1.30eV. This proved that zincblende VSb is half-metallic ferromagnet with 100﹪spin-polarization at the Fermi level. Moreover, the magnetic moment per formula unit of zincblende VSb is 2.00μB. The calculations of zincblende VSb (001) surface indicate the half-metallicity is destroyed at the Sb-terminated (001) surface, while retained at the V-terminated (001) surface. And the destroy of states of the surface layer, sub-surface layer and the third layer of atoms are very similar to those in the bulk system. In addition, we also found the atomic magnetic moment from the fourth layer, is roughly equal to the bulk value; while changes appear in the upper three atom layers, and the magnetic moment at the surface layer of Vanadium is 2.87μB, which is 0.83μB larger than that in the bulk.Moreover, we calculated the properties at the interface VSb(001)/GaSb(001) and found the interface layer and top layer all maintained good half-metallicity. The density of states at the surface layer atoms have taken place larger changes in the shape and size, but not in the interface layer and the neighboring interface layer compared to that in the bulk system.