Study Of Diluted Magnetic Semiconductor Based On ZnO With Co Doped

The feature sizes of traditional semiconductor process based on charge transportation are close to their limit. Spintronic device have smaller size, lower power consumption, higher speed and the advantages of being nonvolatile. And dilute magnetic semiconductor material is the basis of the realization of spintronic electron devices. ZnO has attracted a lot attention in the field of diluted magnetic semiconductors because of its excellent photoelectric properties, nontoxic and cheapness, especially the realization in theory of room temperature ferromagnetism. But few researchers pay attention to its semiconductor characteristics.Samples were prepared through solid and liquid phase methods, and their crystal structure, surface morphology, ferromagnetism at room temperature, and electrical characteristics were systematically characterized. This paper's main research results are as follows:?1? Cobalt doped ZnO ceramic samples, Zn_1-xCo_xO?x = 0.02,0.05,0.08?, were prepared by solid state method and implanted with Al³⁺. XRD patterns show that all the samples have a single pure phase with wurtzite structure without any metal Co or Al or their oxide cluster, suggesting that Co2+ and Al³⁺ occupied Zn2+ sites in the ZnO crystal lattice. SEM images show that surface of samples are uniform and compact. All samples exhibit room temperature ferromagnetism?RTFM? with positive correlation to content of Co2+. We think the magnetic behavior can attribute to surface defects and Co doped. Hall testing results show that Zn_1-xCo_xO ceramic samples' conduction characteristics can be improved by implanted with Al³⁺. The level of carrier concentration is from 1016/cm3 to 1017/cm3 and electron mobility is 4¹2 cm2/Vs.?2? In order to obtain a higher purity and higher doping uniformity of powder materials to sinter high-performance ceramic target, Cobalt doped ZnO powder samples, Zn1-xCox O?x = 0,0.03,0.07,0.11?, were prepared by sol-gel and hydrothermal method combined. XRD patterns show that all the samples have a single pure phase with wurtzite structure suggesting that Co2+ occupied Zn2+ sites in the ZnO crystal lattice. SEM images show that crystal grains of cobalt doped Zn O are hexagonal cone or spheroidal. Measurement of magnetism indicates that all the samples exhibit room temperature ferromagnetism?RTFM?. The magnetic behavior can attribute to surface defects and Co doping.