| Since the giant magneto-resistance (GMR) effect in Fe/Cr was found, the structure and colossal magneto-resistance effect of the rare earth perovskite La1-xAxMn03 (A= Ca2+, Sr2+, Ba2+...) was paid more attention. Now the theory can be used to explain of colossal magneto-resistance effect were Zner double exchange model (double exchange, DE) and Jahn-Teller effect. The study found that colossal magneto-resistance effect of manganese oxide is obvious in recent years, but the Curie temperature of manganese oxide was too low and the manganese oxide was required magnetic-field too great and have badly stability. Most of the attention focus onⅡA alkaline earth metal, doped divalent transition metals Zn is rare. Doped divalent Zn film is still blank, the nature of thin film is generally better than the bulk. Therefore, doped Zn2+in the A-site, by RF, sputtered on LaAlO3 and SrTiO3, thin films were annealed. Study the affect in the B-site by doped Zn2+in the A-site and the B-site. Using XRD,AFM,XPS,SEM,four-probe methods to study the structure,microstructure,surface,chemical states,magnetic properties of films and bulksThe study results show that:1. The films annealed at 900℃formed stable epitaxial structure between grains and the substrate.2. Lao.5Zno.5Mn03_s/LAO and La0.3Zn0.7MnO3-δ/STO films were growth well, at a temperature of 300K; giant magneto-resistance can be as high as 25%and 28% respectively under the 1.5T magnetic field.3. Lao.7 (Sr1-xZnx) 0.3MnO3-δ(x=0.3)/LAO thin films were growth well, grain radius were decreased. At a temperature of 300K, giant magneto-resistance can be as high as 31% under the 1.5T magnetic field.4.. Lao.7Zno.3 (Mn1-xZnx) O3 (x= 0.05), analyzed by X-ray diffraction and scanning electron microscopy (SEM), results show that the more doped Zn2+, the more grains of polycrystalline becoming large and the more obvious gaps. At a temperature of 300K, giant magneto-resistance can be as high as 19.8%under the 1.5T magnetic field.
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