Preparation And Magnetism Of ZnO Diluted Magnetic Semiconductors Bulk Samples

Diluted magnetic semiconductors (DMSs), i.e., semiconductors doped with magnetic metallic elements, have been the frontier research objects in the field of condensed state physics and material science because of the possibility of assembling charge and spin degrees of freedom in a single substance. As one of the II–VI compound semiconductors, ZnO has drawn much attention because theoretical studies predicted room-temperature ferromagnetism in a semiconducting ZnO recently, normally n type, when doped with suitable magnetic ions. In this thesis, magnetic transition metallic(TM) elements were introduced into ZnO by a standard solid-state reaction method, the magnetization behaviors and the origin of ferromagnetism of Zn1-xTMxO samples were studied. The main content of the thesis is as follows:In chapter one, the study background and application perspectives of DMSs are introduced. Some of basic properties of DMSs and ZnO, such as lattice structure, energy gap, etc. are also reviewed.In chapter two, the preparation process and the possible magnetic interactions of the Zn1-xTMxO samples has been introduced.In chapter three, the structure and magnetization behaviors of Zn1-xTMxO samples have been experimentally investigated. Based on the experiment results, The samples of Mn, Co, Fe, Ni doped ZnO have well magnative behave. Based on the experiment results, the origin of magnetism and the mechanism of magnetic interaction of Zn1-xTMxO are discussed.In chapter four, two methods were used in paraparing the samples of Fe doped ZnO for further research. Based on the result, we find the difference in the samples which used different methods. In construction, the single phase samples can be parapared used coprecipitation method, and using standard solid-state reaction method is difficult to parapare single phase samples. Also, there are a lot of differences in magnetism behaves.