矩形磁纳米点的磁反转及动力学特性研究  

Magnetization Reversal and Dynamical Properties of Rectangular Magnetic Nanodot

作　　者：张光富[1] 陈智全[1] 邓杨保[1] 田野[1] 蒋练军[1] 

机构地区：[1]湖南城市学院通信与电子工程学院,湖南益阳413000

出　　处：《湖南城市学院学报（自然科学版）》2017年第1期62-66,共5页Journal of Hunan City University:Natural Science

基　　金：国家自然科学基金项目(11547186;11547163;11604091);湖南省教育厅科研项目(16B048)

摘　　要：基于微磁学模拟方法研究了矩形纳米点的磁反转和动力学特性.获得了矩形纳米点的磁反转过程、自旋波本征动力学特性,以及两者间的内在联系.矩形纳米点的磁反转过程从边缘畴壁的失稳开始,伴随着边缘畴壁移出纳米点外微磁结构从"Flower"态转变为"C"态,随着"C"态边缘畴向磁体中央扩展形成大角畴壁,最后伴随着畴壁移出纳米点外实现反转.磁反转过程中微磁结构相变总是伴随着某种自旋波模式的软化;对称的边缘模式(S-EM)模式软化诱发微磁结构从"Flower"态向"C"态演化,在反转场附近,局域于Y形畴壁的Y-D畴壁模式自旋波的软化激发矩形纳米点不可逆磁反转.The magnetization reversal and dynamic properties of rectangular magnetic nanodot are studied by micromagnetic simulations. The magnetization reversal process, the dynamical properties, and the internal relation between them are obtained. The reversal begins with the instability of two end domain walls. The magnetization configuration from flower state to C-shape state is accompanied by the motion of the two end domain walls toward outside of the nanodot. The two end domain walls of C-shape state meet at the centre and form a large angle domain wall. Finally, the reversal is achieved by the large angle domain wall move out of nanodot. The magnetization reversal has a close relation with dynamic properties of magnets, which is magnetization transition from one configuration to another is accompanied by softening of one of the spin wave modes. It is the softening of the symmetric edge mode spin wave that triggers the magnetization reversal transition from the Flower state to the C-shape state, While, the irreversible reversal is induced by the softening of the Y-D mode.

关 键 词：自旋波模式 磁反转 微磁学模拟 软模 磁动力学 

分 类 号：O441.2[理学—电磁学] O482.5[理学—物理]