First-Principles On The Half-Metallic Ferromagnetism Of Zinc-Blende Structure

Spintronics, at the cross of magnetism, electronics, and informatics, is a new emerging field of research in considerable expansion. It can use both electronic charge and spin for information storage and processing. The advantages of the spintronic devices would be nonvolatility, increased date processing speed, drcreased electric power consumption and increased integration densities compared with conventional semiconductor electronic devices. At present one of the key problems is to find the spintronic materials with high rate of spin polarization and high Curie temperature. Half-metallic ferromagnet has a high Curie temperature and almost 100% spin polarization. Therefore, it will be the perfect spin injection fountain to semiconduntor. In this paper, we used the full potential augmented plane wave within the density-functional theory to obtain half-metallic ferromagnets.Firstly, the application prospect and fundamental characteristics of diluted magnetic semiconductor and HMF are introduced. The bastic concept of DFT and simulating software are described.Secondly, we calculated that ScM (M=C, Si, Ge, Sn) in the zinc-blende structure. We analyzed spin-polized density of states, energy band, magnetic moment and total energy. Results show that ScM (M=C, Si, Ge, Sn) in the zinc-blende are true half-metallic ferromagnets with 1.00μB. The absolute values of cohesive energies of these ZB compounds are larger than that of ZB CrSb, which has been fabricated experimentally. These compounds could be useful in spin-electronic and other applications.Thirdly, electronic structure and magnetic properties of transition-metal-Cr doped ternary systems based on ZB CdSe compound are systematically explored before and after relaxation. The results show that half-metallic ferromagnets is obtained in the Cr-doped systems with an integer value of 4.00μB per unit cell. These compounds are compatible with traditional semiconductor in the structure, which make materials possible candidates for spin injection in spintronic device.Finally, we calculated that TcM (M=C, Si, Ge) in the zinc-blende structure are half-metallic ferromagnets. Spin-polized density of states, magnetic moment, energy band are calculated in the equilibrium lattice constant. ZB TcM (M=C, Si, Ge) could be useful in spin-electronic and other applications.