Ta缓冲层厚度对FeMn/NiFe体系交换偏置的影响

Effect of Ta buffer layer thickness on the exchange bias of FeMn/NiFe system

用X射线衍射仪、原子力显微镜和磁强计研究了Ta缓冲层厚度变化时,Ta/FeMn/NiFe/Ta多层膜微观结构和磁性能的变化,分析了其微观结构和磁性能之间的关系。实验结果表明,随Ta缓冲层厚度增加,FeMn层织构、晶粒尺寸、位错密度、应变和界面粗糙度都发生明显变化,并且这些变化影响了多层膜的偏置场(Hex)和矫顽力(Hc)的大小。结合实验现象和交换偏置(EB)的物理本质,讨论了微观结构对交换偏置的影响机理。

Microstructures and magnetic properties of the Ta/NiFe/FeMn/Ta system with Ta buffer layer thickness varying were investigated by X-ray diffraction,atomic force microscope,and vibrating film magnetometer,respectively.Experimental results show that FeMn texture,grain size,dislocation density,strain rate and interface roughness changed a lot with the thickening Ta buffer layer.And the change of microstructures finally acts on the values of bias field（Hex）and coercivity（Hc）.Combining with the experimental results and the physical essence of exchange biasing（EB）,we analyzed the mechanism of microstructures change on EB.