Barkhausen Jump Amorphous Ribbon Sensor by Means of Inducing Herical Anisotropy

利用非晶态材料显著的磁性可控性，通过引入局域感应各向异性引起的磁区壁钉扎，成功地制备了巴克豪森跳跃传感器元件。巴克豪森跳跃传感器元件可以在绕组中产生尖锐的脉冲电压，从而可以应用于可靠的旋转编码器传感器和无电源的方向传感器。主要研究结果如下：(1)退火过程中，在磁畴壁所在的区域很容易产生各向异性。该区域作为反向磁区的形核中心和磁区壁的钉扎中心，具有较好的再入特性。(2)即使在短时间的退火过程中，引入的钉扎力也很大，导致反向磁区在带端成核，并突然长大，参与磁通跳跃。因此，脉冲电压的抖动(-Do/dt)很大。(3)非晶态材料的壁宽可达2微米，并且随着诱导的各向异性而增大，从而增加了壁内的各向异性能，从而与交换能相平衡。

Depending on the remarkable controlability of magnetic properties in amorphous materials, an effort was made successfully to fabricate the Barkhausen jump sensor elements by means of introducing the domain wall pinning caused by the locally induced herical anisotropy. The Barkhausen jump sensor element can generate the sharp pulse voltage in windings, then can be applied to reliable rotary encorder sensor and directional sensor without power supply. The research results are summarized as follows,(1) The herical anisotropy can be easily induced by annealing into the region where the domain wall exists during annealing. This region works as nucleation sites of reverse domain and pinning centers of domain walls and the re-entrant properties can be available.(2) The pinning force introduced even in short annealing time is fairly large, so that the reverse domain nucleates at the ribbon ends and grows abruptly to participates in the flux jump. Consequently, the jitter of pulse voltage (-do/dt) is large. To improve that precise control of wall pinning force is needed.(3) The wall width of amorphous materials is as wide as 2mu m, and increases with the induced herical anisotropy to increase the anisotropy energy in the wall which makes balance with the exchange energy.