Strongly enhanced Gilbert damping anisotropy at low temperature in high quality single-crystalline Fe/MgO (001) thin film
Strongly enhanced Gilbert damping anisotropy at low temperature in high quality single-crystalline Fe/MgO (001) thin film
复制标题
高质量单晶 Fe/MgO (001) 薄膜在低温下强烈增强吉尔伯特阻尼各向异性
DOI：
10.1016/j.jmmm.2019.165950
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发表时间：
2020
影响因子：
2.7
通讯作者：
Cheng Zhao-hua
中科院分区：
文献类型：
--
作者：
Zhang Wei;Li Yan;Li Na;Li Yang;Gong Zi-zhao;Yang Xu;Xie Zong-kai;Sun Rui;Zhang Xiang-qun;He Wei;Cheng Zhao-hua
吉尔伯特阻尼的各向异性行为为控制和调谐同一磁性器件内的磁化弛豫提供了新的维度。具有高对称性的单晶铁磁金属在近十年来一直被预测具有显著的各向异性阻尼。当温度降到T = 4.5K时，我们发现Fe（15nm）/MgO（0.01）的各向异性阻尼因子Q（定义为易磁化轴和难磁化轴之间的阻尼之差）可以接近60%-90%，而不依赖于外加场。它比在室温下获得的Q = 10%-20%大得多。此外，它是随后的解释呼吸费米面模型的基础上给出约Q = 30%-40%时，电子-声子散射率足够小。这一发现将丰富对阻尼机制的理解，并为寻找三维过渡金属及合金的强各向异性阻尼提供线索。
The anisotropic behavior of Gilbert damping provides a new dimension for controlling and tuning magnetization relaxation within the same magnetic device. The single-crystalline ferromagnetic metals with a high symmetry have been predicted to possess significantly anisotropic damping for one decade. By decreasing temperature down toT= 4.5 K, we found that the anisotropic damping factor Q, defined as the fractional difference of damping between easy and hard axis, can be approached to 60%–90% in Fe (15 nm)/MgO (0 0 1) without applied fields dependent behavior. It is much larger than Q = 10%–20% obtained at room temperature. Furthermore, it is followed by explanations on the basis of the breathing Fermi surface model giving around Q = 30%–40% when electron-phonon scattering rate is small enough. This discovery will enrich the understanding of damping mechanism, and can provide clues for searching strongly anisotropic damping within 3d transition metals and alloys.