Giant magnetoresistance in Co–Al2O3 granular films prepared by self-organized growth
- 作者：Shen-Fen Hao ; Bei Fan ; Liang-Min Wang ; Zhao-Gang Zhang ; Tian Yu ; Xing-Qing Li ; Ding-Guo Li ; Qi-Ling Li ; Peng Chen
- 关键词：Giant magnetoresistance ; Granular film ; Distribution of cluster size ; Temperature
- 刊名：Journal of Magnetism and Magnetic Materials
- 出版年：2008
- 期刊代码：31_03048853
- 类别：ph
- 出版时间：August 2008
- 卷：320
- 期：15
- 页码：2062-2067
- 文件大小：575 K
摘要
Co–Al2O3 granular films with a narrow distribution in cluster size of Co clusters embedded in Al2O3 matrix were prepared by sequential deposition based on self-organized growth. Resistivity dependence of giant magnetoresistance (GMR) was studied. The GMR takes a maximum of 5.2%at room temperature and 9.4%at 13 K and 5700 Gs when the resistivity of the sample is 4×105–7×105 μΩ cm. The temperature dependence of resistivities and GMR were discussed especially. A temperature dependence of conductance ρ
exp[T1/(T+T0)] was found, which indicates the dominant conduction mechanism is fluctuation-induced tunneling. A linear relationship of GMR versus T was observed, GMR=a–kT, in applied magnetic field 5700 Gs. The remarkable character of temperature dependence of GMR should be due to the special microstructure that the clusters are monodispersed in the films.
exp[T1/(T+T0)] was found, which indicates the dominant conduction mechanism is fluctuation-induced tunneling. A linear relationship of GMR versus T was observed, GMR=a–kT, in applied magnetic field 5700 Gs. The remarkable character of temperature dependence of GMR should be due to the special microstructure that the clusters are monodispersed in the films.