强磁场下蒸镀法制备Co_3O_4薄膜

Effect of a high magnetic field on evaporation deposition of Co_3O_4 thin films

为了研究强磁场对蒸镀法制备Co3O4薄膜结构影响,以提高该材料的取向性,改善Co3O4薄膜的磁学性能,该文以99.99%的Co为原料,分别在无磁场和强磁场条件下低真空热蒸镀Co3O4薄膜,采用扫描电子显微镜、X射线衍射和振动样品磁强计研究了以Si(111)为基底的Co3O4薄膜晶粒尺寸、取向和磁性能。结果表明:随着磁场强度增加至4T,晶粒尺寸由200 nm减至20 nm,晶体由杂乱取向排列转为平行于磁场方向取向生长,薄膜的矫顽力减小,矩磁比增大至0.81。结果表明:强磁场对蒸镀法制备Co3O4薄膜晶粒的大小和取向有显著影响,能显著提高材料的矩磁比。

The orientation of Co3O4 thin films and their magnetic properties depend on the magnetic field strength during vacuum evaporation deposition of Co3O4 thin films. These effects were evaluated in the experiments using cobalt of 99. 99% purity as the raw material and Si （111） as substrates. The evaporation pressure was 0. 1 Pa and the magnetic fields were 0 - 4 T. The crystal size, orientation and magnetic performance were measured by scanning electronic microscope （SEM）, X-ray diffraction （XRD）, and vibrating sample magnetometer （VSM）. Increasing the magnetic field from 0 T to 4 T reduced the grain size from 200 nm to 20 nm, Hc was reduced to 150 Oe and Mr/Ms was increased to 0. 81. The results indicate that high magnetic fields during evaporation deposition significantly influence the microstructure and crystal orientation of Co3O4 thin films and greatly improve Mr/Ms.