Picosecond wide-field magneto-optical imaging of magnetization dynamics of amorphous film elements
Picosecond wide-field magneto-optical imaging of magnetization dynamics of amorphous film elements
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DOI：
10.1103/physrevb.90.054410
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发表时间：
2014-08-15
影响因子：
3.7
通讯作者：
McCord, Jeffrey
中科院分区：
文献类型：
--
作者：
Mozooni, Babak;von Hofe, Thomas;McCord, Jeffrey
利用具有皮秒时间分辨率和相位锁定谐波激励的时间分辨宽场磁光显微镜对软磁厚膜元件中磁畴和畴壁态的基本动力学模式进行成像。通过分析镜像磁畴状态，同时提取了连续微波激励下的纯面内和面外动态磁响应。畴壁振荡和局部域响应，包括横向对齐和封闭域状态，可视化以下，在，和以上的磁性元件的共振频率。不同的高频磁导率的区域区分从横向解决的测量。尽管几乎恒定的进动频率，一个强大的模式振幅的变化被发现与变化的偏置磁场，这是相关的表现出的变化的个人域结构。在各个区域内的非均匀异相进动模式发生在接近区域不稳定的状态。成像结果进行了比较，现有的模型的通量响应。磁畴知识和精确的动态成像是需要的动态磁化行为的理解，即使是基本的域结构超出了磁性材料的基本属性。
Time-resolved wide-field magneto-optical microscopy with picosecond time resolution and with phase-locked harmonic excitation is used to image the fundamental dynamic modes of magnetic domain and domain-wall states in soft-magnetic thick film elements. By analyzing mirrored domain states, the pure in-plane and out-of-plane dynamic magnetic response under a continuous microwave excitation is extracted simultaneously. Domain-wall oscillations and local domain response, including transversely aligned and closure domain states, are visualized below, at, and above the resonance frequency of the magnetic elements. Regions of different high-frequency permeability are distinguished from the laterally resolved measurements. Despite nearly constant precessional frequency, a strong mode amplitude variation is found with varying the magnetic bias field, which is correlated to the exhibited change of the individual domain structure. Inhomogeneous out-of-phase precessional modes within the individual domains occur close to a state of domain instability. The imaging results are compared to existing models of flux response. Magnetic domain knowledge and precise dynamic imaging is needed for the understanding of the dynamic magnetization behavior of even basic domain structures beyond the magnetic material's elementary properties.