Exchange-coupling modified spin wave spectra in the perpendicularly magnetized Permalloy nanodot chain arrays
Exchange-coupling modified spin wave spectra in the perpendicularly magnetized Permalloy nanodot chain arrays
复制标题
垂直磁化坡莫合金纳米点链阵列中交换耦合修正的自旋波谱
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
M. Carey
中科院分区：
文献类型：
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作者：
Jian Dou;S. Hernandez;Chengtao Yu;M. Pechan;L. Folks;J. Katine;M. Carey
利用铁磁共振研究了交换耦合纳米点链阵列中的自旋波谱。利用电子束曝光法制备了直径为300 nm、厚度为40 nm的点链阵列，通过宽度从0(无桥)到60 nm的坡莫合金桥耦合。在垂直磁化的孤立点中，观察到多个尖锐的铁磁共振峰，它们与量子化的面内波矢有关，这是由于有限的点半径所致。由于有效退磁因子的增加，对于具有更宽电桥的样品，这些谱线向更高的场移动。对于耦合的点，在高阶自旋波模的两侧和均匀模的低场侧观察到附加的卫星峰。我们证明，这些卫星峰可以分别归因于每个桥点的激发和点间交换耦合。
Spin wave spectra in exchange-coupled nanoscale dot chain arrays were studied using ferromagnetic resonance. The dot chain arrays, with dot diameters of 300 nm and thicknesses of 40 nm, coupled via Permalloy bridges of width ranging from 0 (no bridge) to 60 nm, were fabricated using e-beam lithography. In the perpendicularly magnetized isolated dots, multiple sharp ferromagnetic resonant peaks were observed, which are associated with the quantized in-plane wave vector due to the finite dot radius. These spectrum lines shift to higher fields for samples with wider bridges due to the increasing effective demagnetizing factor. For coupled dots, additional satellite peaks were observed at both sides of higher order spin wave modes and at the lower field side of the uniform mode. We show that these satellite peaks can be attributed to the excitation in each bridged dot and the interdot exchange coupling, respectively.