微型磁阻元件中磁畴活动和畴壁态极性转变的研究

A Study on Domain Activities and Wall State Transitions in Small MR Elements

采用Bitter粉纹技术详细观察和研究了微型磁阻元件在磁化和反磁化过程中的磁畴结构，结果表明Barkhausen噪声来源于磁化和反磁化过程中的磁畴活动和畴壁态极性转变。磁阻元件中的曲折状畴的产生、强化和畴壁合并及畴壁态极性转变是不可逆过程，是磁阻元件输出信号噪声的主要根源。实验发现，在磁阻元件和引线的连接处存在着磁畴结构，且这一过程是不可逆的。目前尚未见过报道。这必然也是磁阻元件输出信号噪声的来源之一。

Domain patterns in small MR elememts were observed and investigated in detail by the Bittertechnique during the magnetization and magnetization reversal process. The results show that the Barkhausennoise originates from domain activities and wall state transitions,and the irreversible process of creation,intensification, mergence,annihilation and wall state transition of well-defined buckling domain structures are responsible for the signal output noise in small MR elements. It was observed in the experiments that domain structures could exist in the junction between the leads and the MR element,and was one of the signal output noise of MR elements.