Controllable Interfacial Coupling Effects on the Magnetic Dynamic Properties of Perpendicular [Co/Ni](5)/Cu/TbCo Composite Thin Films
Controllable Interfacial Coupling Effects on the Magnetic Dynamic Properties of Perpendicular [Co/Ni](5)/Cu/TbCo Composite Thin Films
复制标题
可控界面耦合对垂直[Co/Ni]5/Cu/TbCo复合薄膜磁动力学性能的影响
DOI：
10.1021/acsami.7b16978
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发表时间：
2018
影响因子：
9.5
通讯作者：
Zhang Zongzhi
中科院分区：
文献类型：
--
作者：
Tang Minghong;Zhao Bingcheng;Zhu Weihua;Zhu Zhendong;Jin Q Y;Zhang Zongzhi
垂直交换耦合[Co/Ni]5/Cu（tCu= 0-2 nm）/TbCo结构的动态磁性与界面反铁磁强度Jex有很强的依赖关系，而界面反铁磁强度Jex受Cu层间厚度的控制. [Co/Ni] 5多层膜在平行（P）和反平行（AP）磁化取向状态下的旋进频率f和有效阻尼常数α eff明显不同。对于薄Cu的样品，由于TbCo层的单向交换偏置效应（HEB），AP态的f值明显高于P态，而α eff值则低于P态。随着Cu含量的增加，两种态的α效应差逐渐减小。采用一个包含附加HEB项的均匀进动模型，可以很好地拟合出随场变化的频率曲线，拟合的HEB值与实验数据符合得很好。饱和阻尼常数α 0与Jex近似呈线性关系。它随Jex的增加而显著减小，并最终接近0.027 attCu= 2 nm的恒定值，此时Jex消失。这些结果提供了一个更好的理解和有效的控制交换耦合复合结构的自旋电子学应用的磁化动力学。
Dynamic magnetic properties in perpendicularly exchange-coupled [Co/Ni]5/Cu (tCu= 0–2 nm)/TbCo structures show strong dependences on the interfacial antiferromagnetic strengthJex, which is controlled by the Cu interlayer thickness. The precession frequencyfand effective damping constant αeffof a [Co/Ni]5multilayer differ distinctly for parallel (P) and antiparallel (AP) magnetization orientation states. For samples with a thintCu,fof the AP state is apparently higher, whereas αeffis lower than that in the P state, owing to the unidirectional exchange bias effect (HEB) from the TbCo layer. The differences infand αeffbetween the two states gradually decrease with increasingtCu. By using a uniform precession model including an additionalHEBterm, the field-dependent frequency curves can be well-fitted, and the fittedHEBvalue is in good agreement with the experimental data. Moreover, the saturation damping constant α0displays a nearly linear correlation withJex. It decreases significantly withJexand eventually approaches a constant value of 0.027 attCu= 2 nm whereJexvanishes. These results provide a better understanding and effective control of magnetization dynamics in exchange-coupled composite structures for spintronic applications.