温度、缺陷对磁畴壁动力学行为的影响  

Influences of material defects and temperature on current-driven domain wall mobility

作　　者：朱金荣[1] 范吕超 苏垣昌[1] 胡经国[1] 

机构地区：[1]扬州大学物理科学与技术学院,扬州225002

出　　处：《物理学报》2016年第23期262-268,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11374253);江苏省高校自然科学研究基金(批准号:16KJB140018)资助的课题~~

摘　　要：基于Landau-Lifshitz-Gilbert自旋动力学方法,研究了磁纳米条中缺陷、温度对其电流驱动磁畴壁移动性质的影响.研究结果表明:缺陷能有效钉扎电流对磁畴壁的驱动作用,并且其钉扎能力依赖于其缺陷浓度、位置及形态.而温度能有效地去钉扎.特别地,缺陷处的焦耳热能有效地消除其缺陷对磁畴壁的钉扎作用.进一步的研究表明:其影响磁畴壁移动的缘由在于缺陷、温度能有效调节磁纳米条中磁畴壁的面外磁化强度.Current-induced domain wall motion, which has potential application in the next-generation data storage and logic device, has attracted much interest in recent years. However, how the material defect and its joule heat influence currentdriven domain wall motion in magnetic nanostripe is still unclear. This paper is to deal with these issues by using the Landau-Lifshitz-Gilbert spin dynamics. The results show that the material defect can pin domain wall motion and this pinning effect strongly depends on the defect concentration, location and shape. The pinning effect induced by the defect on domain wall motion results in the increase of threshold current, and the domain wall moves steadily and continuously.Specifically, the probability for domain wall motion induced by pinning effect is nonlinearly increasing with the increase of defect concentration. Namely, the increasing of the pinning ability with the increase of the defect concentration becomes fades away. Initially, when the defect is near to domain wall, the pinning ability is obvious. However, the pinning ability is not linearly increasing with the decrease of the initial distance between the defect and the domain wall.The results also show that the single defect is larger, the probability for domain wall motion induced by defect pining is bigger. Moreover, the material defect can suppress the domain wall trending toward breakdown and make domain wall move faster, but the suppressing ability is not obviously increasing with the increase of the defect concentration. On the other hand, the temperature field can remove the pinning phenomenon, which will result in the threshold current decrease. The decrease of the threshold current is of benefit to the working of the data storage and logic device. Also the temperature field can suppress the domain wall trending toward breakdown, but the suppressing ability is less than that of the defect. In addition, the Joule heat around defects can obviously eliminate the pinning effect of the defects,so the pinning effect

关 键 词：磁畴壁 电流驱动 缺陷 温度 

分 类 号：O482.5[理学—固体物理]