非晶Co/Ge多层膜的磁性和电性能

Magnetic and Electrical Properties in Co/Ge Amorphous Films

采用射频溅射的方法制备了[Cox/Ge10-x]（x=0.1,0.3,0.5,0.7,1.0,1.5,2.5 nm）非晶多层薄膜,X射线衍射仪（XRD）显示样品中不存在第二相.随着Co层厚度增加,室温下薄膜磁性由抗磁性转变为铁磁性.制备态的[Co2.5/Ge7.5]的饱和磁化强度Ms可达8.3×104 A/m.霍尔效应测试表明样品均为P型半导体,载流子浓度约为1023～1025 m-3.薄膜的低温电阻导电机理属于磁性半导体材料的自旋依赖电子变程跃迁机制,实验结果表明,Co/Ge体系有作为新型自旋电子学器件材料的可能.

The [Cox/Ge10-x] （x=0.1,0.3,0.5,0.7,1.0,1.5,2.5 nm） amorphous multilayer films were fabricated by RF sputtering method.The XRD showed that second phase did not exist in these samples.With increasing thickness of Co layer,the magnetic properties of the samples changed from diamagnetism to ferromagnetism at room temperature.The saturation magnetization Ms was up to 8.3 × 104 A/m in the as-sputtered [Co2.5/Ge7.5] film.Hall-effect tests showed that all samples were P-type semiconductor,with the carrier concentration about 1023-1025 m-3.The conductive mechanism belonged to the spin dependent variable range hopping resistance in the low-temperature.The experimental results showed that amorphous Co/Ge system would be a potential candidate of the new spintronic device materials.