compatible with Si spintronics materials research: magnetic semiconductor

Title: compatible with Si spintronics materials research: magnetic semiconductorAuthor: Jiaxing TaoDegree awarded: China University of PetroleumKeywords: spin electronics;; magnetic semiconductor;; density functional theory;; half-metallic ferromagnetism;; Si;; Delta dopingSummary:
Spintronics while taking advantage of the electronic charge and spin two attributes, internal to the device to achieve the electric and magnetic coupling, a new generation of electronics. Spintronics spintronics materials is now the key issue, Si is the foundation of modern electronics industry. Achieve spintronics materials with Si semiconductor technology will greatly facilitate the Neodymium Magnets integration of semiconductors - the development of spintronics. Therefore, exploration and Si-compatible materials, spintronics is important. Papers focus on the compatibility with Si to (Zn, Cr) S, (Ga, Mn) P and MnxSi1-x as the main object of study, based on first-principles density functional calculations of the zinc oxide compounds, III-IV and group IV magnetic semiconductor doped magnetic and magnetic generation mechanism. In addition, the paper also discusses the new wide band gap insulator oxides ZrO2 and HfO2-based magnetic semiconductors and magnetic doping in these materials to the semiconductor spin injection.
In Chapters II and III, the papers in (Zn, Cr) S and (Ga, Mn) P system as the main object of study of the zinc oxide and III-IV compound semiconductor doped magnetic magnetic and thermodynamic properties. Studies have shown that transition metal atoms tend to reunite the semiconductor substrate in the formation of delta-doped plane, delta-doped configurations tend to have enhanced two-dimensional magnetic. Thesis system investigated (Zn, Cr) S and (Ga, Mn) P single-layer, semi-layer, double delta doping and delta doping close to some of the configuration of configuration (refer to atoms by short-range migration can be transformed into configuration of delta-doped structure type) and the magnetic energy state. Studies have shown that, (Zn, Cr) S structure of all research-type doping has half-metallic ferromagnetism; (Ga, Mn) P and a half single-layer configuration with delta-doped http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets semi-metallic ferromagnetism, while the double is antiferromagnetic. The paper also examines the different planes of the delta doping. Studies have shown that in the (Zn, Cr) S and (Ga, Mn) P high-symmetry (001) surface configuration of the delta-doped often with enhanced two-dimensional half-metallic ferromagnetic (ferromagnetic stability and higher theoretically maintain the half-metallic ferromagnetic temperature), and in the low-symmetry (111) and (110) surface is ferromagnetic or ferromagnetic loss weakened. Doping configuration of the magnetic properties of magnetic semiconductors can be used ligand field theory and the Jahn-Teller theory to explain.
In the fourth chapter, the paper system to explore the MnxSi1-x delta-doped magnetic semiconductors of different magnetic configurations. Studies have shown that the high symmetry on Si (001) surface than in the low-symmetrical delta-doped (111) and (110) ferromagnetic surface is more stable; in Si (001) surface with a low concentration of single-layer delta-doped half-metallic ferromagnetism, while the half-layer and multilayer semi-metallic nature is lost. MnxSi1-x magnetic semiconductors can be used with the origin of the magnetic field theory description. And (Zn, Cr) S and (Ga, Mn) P difference, delta doping MnxSi1-x magnetic semiconductors to improve but to maintain the stability of the ferromagnetic half-metallic ferromagnetic temperature decrease. In addition, the paper also discusses the Si1-xGex alloy and SiC doped magnetic.
In the fifth chapter, the paper examines the new wide band gap insulator oxides ZrO2 and HfO2-based magnetic semiconductors and magnetic doping such materials to the semiconductor spin injection. Studies have shown that hot-electron injection mechanism can achieve ballistic poor compatibility with the Si magnetic or ferromagnetic semiconductor spin injection to the Si. Paper examines the (Zr, Mn) O2 and (Hf, Mn) O2 special electronic structure of ballistic hot-electron injection mechanism in the application. Paper pointed out that the use of these two materials as a spin filter material not only at the Fermi level to achieve 100% spin-polarized injection, but also in a wide range of hot-electron energy levels to achieve 100% spin-polarized injection. Thesis observed in the electron injected into the semiconductor by adjusting the spin direction of the hot electron energy modulation, which could control the direction of the electron spin generated applications.
Papers in each chapter also discusses several common 3d transition metal atoms in the ZnS, GaP, Si and ZrO2 (001) surface of delta-doped magnetic. Studies have shown that doping of magnetic atoms have a decisive influence on the doping.
Papers in the second chapter also explores the substrate crystal structure and magnetic effects of stress on the doping. Studies have shown that the higher symmetry of the substrate crystal structure, the higher the stability of the system ferromagnetic; general, the stress on the magnetic semiconductor magnetic influence. But studies show that a large range of stress on the cubic (Zn, Cr) S semi-metallic nature of the stability and have little effect. In addition, the papers in the second chapter also discusses the delta zinc chalcogenides doped extreme cases - cubic magnetic transition metal sulfides. Paper pointed out that the cubic VS, VSe, VTe, CrS, CrSe and CrTe other potential spintronics application.
Chapters 2 and 3 in the second paper also discusses some of the Si has good compatibility with the zinc-sulfur compounds and III-IV delta-doped semiconductor and magnetic alloys. Studies have shown that cubic (Zn, Cr) Se, (Ga, Mn) As, (Al, Mn) P, (Al, Mn) As, (Ga, Mn) PxAs1-x and (Ga1-xAlx, Mn) P, etc. and so a stable half-metallic ferromagnetism. In addition, the paper also discusses some of the poor compatibility with the Si of the delta-doped magnetic semiconductor materials, such as cubic (Zn, Cr) O, (Zn, Cr) Te, (Ga, Mn) Sb, (Al, Mn ) Sb, (In, Mn) Sb, (In, V) N and (In, Cr) N, etc. stable ferromagnetism. Studies have shown that these materials have potential spintronics application.
Paper pointed out, delta-doped semiconductors is expected to be resolved in the doped magnetic transition metal atoms join one of the control problem.Degree Year: 2009