Structure, Optical And Magnetic Properties Of Zn-Mn Complex Metal Oxides

Spinel-type complex metal oxides are important functional materials in fields of magnetic materials, catalyst, stealth materials, battery, radiofrequency dielectric substance and so on. On the other hand, researches on diluted semiconductor are arousing more and more attention now. The Zn-Mn-O system is a potential material system in these two fields for the case that both spinel structure of ZnxMn3-xO4and wurtzite structure ZnxMn1-xO are included in this system. But in fact, we are lack of elementary knowledge about ZnxMn3-xO4and ZnxMn1-xO, especially the room temperature ferromagnetism from them.In our experiments, we have carried out a series of spinel structure of ZnxMn3-xO4. In addition, we have improved a high temperature-organic-chemical method to synthesized ZnxMn1-xO successfully. The thesis discusses the structure, composition, optical and magnetic properties of Zn-Mn-O system. More retails are listed as follow:(1) ZnxMn3-xO4were carried out by hydrothermal method. ZnxMn1-xO were carried out by high temperature organic chemical method.(2) We studied different structures of ZnxMn3-xO4and came to a conclusion that the spinel structure can be classified into two types:cubic spinel structure and tetragonal spinel structure. Meanwhile, we discussed different experiments condition associate with different spinel structures.(3) The valence of Mn in various structure of ZnxMn3-xO4were specified by X-ray photoelectron spectroscopy. It indicated that there are both Mn3+and Mn4+in cubic spinel ZnxMn3-xO4and only Mn3+in tetragonal spinel ZnxMn3-xO4. What’s more, the Raman spectrums of these series of Zn-Mn-O system are gave out firstly.(4) Room temperature ferromagnetism (RTF) comes from the sample with both cubic ZnxMn3-xO4and tetragonal ZnxMn3-xO4. The case indicates RTF is induced by double exchange between Mn3+and Mn4+on the interface. Single phase of cubic ZnxMn3-xO4and tetragonal ZnxMn3-xO4are all paramagnetism. Meanwhile, ZnxMn1-xO is demonstrated to be paramagnetism by hysteresis loop test.