Magnetization precession and damping in Co2FeSi Heusler alloy thin films
Magnetization precession and damping in Co2FeSi Heusler alloy thin films
复制标题
Co2FeSi Heusler 合金薄膜中的磁化进动和阻尼
DOI：
10.1016/j.jmmm.2019.01.087
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发表时间：
2019
影响因子：
2.7
通讯作者：
Zhang Zongzhi
中科院分区：
文献类型：
--
作者：
Zhu Weihua;Zhu Zhendong;Li Dong;Wu Guanjie;Xi Li;Jin Q Y;Zhang Zongzhi
利用时间分辨磁光克尔效应（TR-MOKE）研究了Co2 FeSi全Heusler合金薄膜的磁化动力学。对于衬底温度低于350 °C的样品，由于强的主旋进模和弱的附加模共存，TR-MOKE信号出现明显的双频现象。随着Ts的增加，附加高频模式的振幅减小，并且变得不可检测。相反，在最高外场H = 15 kOe时测得的磁阻尼参数α 0，对于低T_s的样品仅为0.004，在T_s> 350 °C时急剧上升，在T_s = 480 °C时达到0.023。我们把磁阻尼的增加归因于晶界处双磁振子散射的增强。本研究对Heusler合金薄膜的自旋旋进和磁阻尼行为有了较全面的了解，这将有助于高频自旋电子器件的开发。
Magnetization dynamics of Co2FeSi full Heusler alloy films have been investigated by time-resolved magneto-optical Kerr effect (TR-MOKE). For the samples grown at a substrate temperature (Ts) lower than 350 °C, an obvious dual frequency phenomenon is found in the TR-MOKE signals due to the coexistence of a strong main precession mode and a weak additional mode. The amplitude of the additional high frequency mode decreases and becomes undetectable with increasingTs. On the contrary, the magnetic damping parameterα0measured at the highest external field ofH= 15kOe is as low as 0.004 for lowTssamples, it rises abruptly atTs> 350 °C and even reaches 0.023 atTs= 480 °C in spite of the improved atomic ordering. We attribute the greatly increased magnetic damping to the enhanced two-magnon scattering occurred at grain-grain boundaries. This study provides a comprehensive insight into the spin precession and magnetic damping behaviors of Heusler alloy films, which will be helpful for developing high frequency spintronic devices.