The Investigation On Growth And Properties Of Fe Based Wide-gap Ⅱ-Ⅵ Group Diluted Magnetic Semiconductors And FeSe Heterostructure

Spintronics is a new discipline at the border between magnetism and electronics, developed quickly in the end of the 20th century. At present, two kinds of spintronic materials have received much attention: one is the dilute magnetic semiconductors (DMS), the other is the ferromagnet/semiconductor hybrid materials. These both materials, combining conventional semiconductor and magnetic materials, become a new focus on the technological and industrial field because which can be make new generation of spintronics device.In this thesis, aiming at the hotspots and difficulty in DMS and ferromagnet/semiconductor hybrid materials, the preparation and characterization of the ZnFeS, ZnFeO, FeSe and ZnS was realized. The the major fruits are listed below:(1) A series of the ZnFeS thin films with different Fe content are prepared by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) equipment. The X-ray diffraction (XRD) patterns indicated that ZnFeS with single-crystal hexagonal structure was obtained when gas flow rates of Fe(CO)5 was less than 6ml/min. When gas flow rates of Fe(CO)5 excessed 6ml/min, ZnFeS polycrystalline with cubic structure was obtained. Furthermore, the energy gaps of the samples narrowed significantly with increasing Fe content. The XPS spectra showed that the S 2p shifted towards higher binding energies side due to the fact that the bond strength of Fe-S is larger than that of Zn-S.(2) A series of the ZnFeS thin films were annealed in oxygen atmosphere at different temperature. It was found that the sample have a high crystal quality at annealing temperatures of 800℃. Magnetic measurement showed that the ZnFeO thin films annealed at 800℃have ferromagnetic properties at room temperature. Furthermore, the limit of the solution of the Fe in ZnO is close to 0.25 in our work.(3) High-quality FeSe thin films were grown on GaAs (001) substrates using LP-MOCVD. X-ray diffraction patterns showed that FeSe thin films were in tetragonal structure with unitary orientation. Magnetic measurement indicated that the Curie temperatures of FeSe thin films are above room temperature. It was found that the FeSe films have a strong magnetic anisotropy between the in-plane and out-of-plane magnetization with in-plane magnetic easy axis. Moreover, the measurements of absorption spectrum, magnetic circular dichroism (MCD) spectra, and temperature dependent resistivity give believable evidence that the FeSe is Ferromagnetic semiconductor properties.(4) The vertical-aligned ZnS nanorods arrays were prepared by the activity effect of plasmas. It is believed to provide an additional energy to enhance the...