钴基非晶薄带交换偏置现象稳定性和可控性的研究

Stability and controllability of Co-based amorphous ribbon with exchange bias behavior

钴基(Co58Fe5Ni10Si11B16)非晶薄带在一定温度范围内做热磁处理之后,由于薄带内有少量磁性较硬结晶相析出,其磁矩对非晶软磁基体的钉扎作用使样品出现交换偏置行为。在研究过程中采用X射线衍射仪、高分辨透射电镜表征样品相组成及微观结构,利用冲击检流测量法测试其磁滞回线,通过扫描探针显微镜观测薄带表面磁畴,由此深入分析内在磁矩配置情况。结果表明,在利用横向冲击场调控钴基薄带交换偏置行为的过程中存在临界场。当横向冲击场低于临界场时,结晶相磁矩几乎不受其影响,交换偏置行为呈稳定状态;而大于临界场时,结晶相磁矩在其冲击作用下按自由能最小原则重新配置,交换偏置行为可通过调节横向冲击场的大小有效调控。

The CoFeNiSiB ribbons,which were annealed in longitudinal field at different temperature,exhibit a considerable exchange bias（EB） behavior.It is found that the magnetically harder crystalline phases play a main role in the appearance of EB behavior in the materials,due to the strong pinning effect.In this paper,the crystallization and microstructures of the samples were characterized via XRD and HRTEM.The hysteresis loops were measured using a ballistic galvanometer.The surface magnetic domains were scanned by the magnetic force microscope.The details of magnetic domains configuration has been analyzed based on the magnetic domain pattern.The results showed that there exist a critical field during the turning operation of the EB behavior by transverse impact filed（HT）.It indicates that EB behavior was hardly changed when HT was smaller than critical field.In the other words,the EB behavior was stable.When the HT was larger than the critical field,the magnetic moment should be reconfigured abide by the principle of minimum free energy.In the process,the EB behavior can be effectively controlled by adjusting the HT.