金属镍的Barkhausen发射特性的研究及磁畴壁运动临界场值的计算

Studies on Characteristics of Barkhausen emission and evaluation of critical fields for domain wall motion in nickel

摘要: 本文研究了金属镍的Barkhausen声发射(ABE)和电磁发射(EDE)的特性。作者利用能量密度图和修正的Kersten理论解释了镍对外加磁场的响应。文中所介绍的测量结果除证实ABE之源为非180°磁畴壁运动引起外,还进而演示了外加磁场变化,使镍从(退出)饱和到反向饱和时,三种磁畴壁运动的顺序依次为:71°,180°和109°。文章阐明了如何用所测到的Barkhausen信号去确定相应于这三种磁畴壁(不可逆)运动的临界磁场值大小。

Abstract: Acoustic Barkhausen Emission (ABE) and Electromagnetic Barkhausen Emission (EBE) have been measured. Explanations of the response of nickel to an applied magnetic field are considered, using energy density diagrams and critical fields deduced by using Kersten's modified theory. These theoretical models are correlated with ABE and EBE measurements, providing further confirmation of the origins of ABE being non-180° domain wall motion. This paper also shows that the motion of domain walls, on increasing the magnetising fields from saturation to saturation, follows the sequence of 71°-180°-109°. Values of critical fields corresponding to 71°, 180ånd 109°wall motions in nickel are determined using these techniques.