【摘要】 利用直流反应磁控溅射方法制备了厚度为480nm,不同掺氧量γ的Fe3O4薄膜,再经过480度80分钟的高温退火处理.系统研究了薄膜的微结构和电、磁输运性质,发现随掺氧量增大,薄膜的电阻率从20.6增大到1100mΩcm,磁滞回线和磁电阻曲线表明在磁特性方面高掺氧量薄膜明显优于低掺氧量薄膜,当掺氧量为0.675∶50时室温下薄膜有最大磁电阻2.1%.X射线衍射表明所有的Fe3O4薄膜都显示出外延生成倾向,磁电阻随温度变化曲线证实薄膜在低温时经历Verwey转变.综合比较表明掺氧量为0.65∶50和0.675∶50的薄膜具有最佳的结构和电磁特性.更多还原

【Abstract】 Magnetite （Fe₃O₄） thin films of 480 nm in thickness have been prepared by dc reactive magnetron sputtering, which were deposited respectively at various ratios of oxygen and argon γ=（P（O₂）:）P（Ar） = 0.50∶50, 0.55∶50, 0.60∶50, 0.65∶50, 0.675∶50 and 0.70∶50. Then the films were post-annealed at 480℃ for 80min. The structural and magnetic transport properties of the films were studied by the analyses of resistivity, X-ray diffraction （XRD）, temperature dependence of resistance, magnetic hysteresis loops, magnetoresistance （MR）, temperature dependence of MR ratio, scanning electron microscopy （SEM） of the films. After annealing, as γ increased, the resistivity of the films increased from 20.6 to 1100 mΩcm. XRD indicated that a high degree of orientational quality was formed for all the films. The magnetic properties of the films for γ>0.60∶50 were better than those for γ≤ 0.60∶50. The maximal magnetoresistance of 2.1% at room temperature appeared at γ=0.675∶50. The films deposited at γ>0.60∶50 showed clear Verwey transition from the MR-T curves. The high-quality Fe₃O₄ thin films could be obtained at γ=0.65∶50, 0.675∶50 with post-annealing at 480℃ for 80min.更多还原