Influence of capping layers on CoFeB anisotropy and damping
Influence of capping layers on CoFeB anisotropy and damping
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DOI：
10.1063/1.4749412
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发表时间：
2012-09
影响因子：
3.2
通讯作者：
A. Natarajarathinam;Z. Tadisina;T. Mewes;S. Watts;E. Chen;Subhadra Gupta
中科院分区：
文献类型：
--
作者：
A. Natarajarathinam;Z. Tadisina;T. Mewes;S. Watts;E. Chen;Subhadra Gupta
研究了覆盖有不同材料（例如 MgO、Ta、Ru 和 V）的 2 nm 至 8 nm 不同厚度的 CoFeB 的磁性行为。这些薄膜经过溅射沉积，随后通过磁力测量和宽带铁磁共振（FMR）进行表征。在与 Ru 和 Ta 覆盖层的界面处观察到磁死层，而 MgO 和 V 对 CoFeB 的磁化几乎没有影响。随着铁磁层变薄，有效磁化强度降低，表明界面垂直各向异性。特别是在 MgO、V/Ru 和 V/Ta 覆盖层的情况下，CoFeB 中会引起界面垂直各向异性，并且吉尔伯特阻尼参数也会降低。这种垂直磁各向异性（PMA）的起源被认为是由自由层和覆盖层之间的界面各向异性引起的。沉积后退火和CoFeB厚度对V/Ta封端合金各向异性和阻尼的影响
Magnetic behavior of CoFeB at various thicknesses ranging from 2 nm to 8 nm capped with different materials, such as MgO, Ta, Ru, and V have been studied. The films were sputter-deposited and subsequently characterized by magnetometry and broadband ferromagnetic resonance (FMR). There are magnetically dead layers at the interface observed with Ru and Ta capping layers, while MgO and V have almost no effect on the magnetization of the CoFeB. As the ferromagnetic layer is made thinner, the effective magnetization decreases, indicating an interfacial perpendicular anisotropy. Particularly in the case of MgO, V/Ru, and V/Ta capping layers, interfacial perpendicular anisotropy is induced in CoFeB, and the Gilbert damping parameter is also reduced. The origin of this perpendicular magnetic anisotropy (PMA) is understood to be caused by the interface anisotropy between the free layer and the capping layer. The effect of post-deposition annealing and CoFeB thickness on the anisotropy and damping of V/Ta capped sa...