Preparations And Properties Of Zn_1-xCr_xO Diluted Magnetic Semiconductors

Diluted Magnetic Semiconductor (DMS), have characteristic of both magnetism and semiconductor, and make use of the spin of electrons in addition to their charge. It has the excellent performace of magnetism, magneto-optical properties, magnetoelectricity and so on. Due to their excellent physical properties, DMS films have many realized and vast potential applications in the field of both material and spinpolarized electronic devices. Nowadays, the researches and developments of DMS films based on zinc oxide which is a wide-gap II -IV semiconductor have attracted great attention and interest from researchers and the industry, because the DMS films based on zinc oxide not only have the synthesis characteristic and extensive appliance, but also can be expected to a high Curie temperature (Tc) and a large magnetization.In this paper, We outline the nature, origins of (ferro) magnetismin DMS, the current status of diluted magnetic semiconductors, and summarize the experimental growth methods and characterization techniques. We deposite respectively ZnO and Cr films by magnetron suttering method. Films of different preferential orientation were deposited by controlling the different working parameters. The thin films samples have been characterized X-ray diffraction (XRD) and other analysis tools to determine the crystal structure and film orientation. Therefore, we optimize the growth condition, and then we measure the film thickness by using the sidestep device in order to obtain the rate of sputtering films which provide the data to control the Zn_1-xCr_xO DMS films thickness in latter experiment.Diluted magnetic semiconductors Cr-doped ZnO films were deposited by using magnetron sputtering apparatus. We studied the concentration of the dopant which has a definite influence on the magnetic properties, structure, transport properties and optics properties of films. At last, we proved that Cr is dopant atoms in amorphous Zn_1-xCr_xO films. The thin films of Zn_1-xCr_xO show the ferromagnetism and obvious hysteresis. We conclude that Cr substituting for ZnO as the origin of ferromagnetism in Cr:ZnO. Cr will be peled on the ZnO crystal interface when the concentration of the dopant Cr is decreasing up to the maximum, and the films optical band gap will hypsochromic shift, with the grow orientation shifting.