Preparation And Magnetism Of Zn-Fe-M-O(M=Cu,Sn) Diluted Magnetic Semiconductors Bulk Samples

Diluted magnetic semiconductors (DMSs) have attracted a great deal of attention because of the possibility of incorporating the magnetic degrees of freedom in traditional semiconductors. DMSs combine their transport and/or optical properties with magnetism, and thereby carry an enormous potential of opening up a path to entirely new devices. Despite intensive efforts on transition metal-doped ZnO thin films, the experimental results did not converge on a definite conclusion; surveying the current situation with transition metal-doped ZnO, one naturally comes to a suspicion that the inconsistent results in thin film DMSs might be due to sensitive dependence of thin films on detailed process conditions. These thoughts motivated us to probe bulk samples rather than thin films. In this paper, we concentrate on Fe-doped ZnO bulked samples prepared by the co-precipation technique, and discuss the impacts Cu/Sn ions playing in the Fe-doped ZnO samples. Through these work, the origin of ferromagnetism was studied. The main investigations were shown as follows:1. We introduce the structure, exchange interactions and magnetic properties of DMSs thoroughly and review the researching progress of ZnO-based DMSs briefly. On the basis of these thoughts, the basic thinking of subject selection and investigation significance is put forward.2. We introduce several kinds of methods for preparation of nano-meter materials. Besides, Zn1-xFexO was synthesized by precipitation method and its structure and magnetic properties were discussed.3. Zn0.98-xFe0.02CuxO samples were synthesized and these structure and magnetic properties were discussed. Besides, we discuss the effects of doping density and sintering temperature in the magnetic properties of samples.4. Zn0.98-xFe0.02SnxO samples were synthesized and these structure and magnetic properties were discussed. Besides, we discuss the effects of doping density and sintering temperature in the magnetic properties of samples.5. We discuss the magnetic properties of Zn0.98Fe0.02O, Zn0.97Fe0.02Cu0.01O and Zn0.97Fe0.02Sn0.01O specially, and the mechanism of magnetism in these samples.In a word, based on room-temperature ferromagnetic Zn-Fe-O diluted magnetic semiconductors, we try to change the carrier density by Sn/Cu doping, and study the magnetic properties of samples. In addition, we try to explore the magnetic origin and improve the magnetism of samples.