Controlling magnetic domain wall motion in the creep regime in He+-irradiated CoFeB/MgO films with perpendicular anisotropy
Controlling magnetic domain wall motion in the creep regime in He+-irradiated CoFeB/MgO films with perpendicular anisotropy
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DOI：
10.1063/1.4927204
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发表时间：
2015-07-20
影响因子：
4
通讯作者：
Ravelosona, D.
中科院分区：
文献类型：
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作者：
Diez, L. Herrera;Garcia-Sanchez, F.;Ravelosona, D.
本研究提出了有效的调谐垂直磁各向异性的CoFeB/MgO薄膜的He+离子照射和磁畴壁运动在低场制度的影响。磁各向异性和饱和磁化强度被发现减少作为辐射剂量的函数，这可以与所观察到的辐射诱导的化学计量的变化在CoFeB/MgO界面。在低磁场（H）下，发现辐照会引起畴壁速度（V）显著降低，从而反映了薄膜磁固有特性的这些变化。对于所有的辐照剂量，畴壁速度在低场很好地描述了蠕变定律，其中Ln（v）与H-1/4的行为线性，最大的字段H*，这已被认为是一个近似的值的退钉场H-dep。反过来，H* 接近H-dep被认为是增加作为辐照剂量的函数，表明辐照诱导的域壁运动的蠕变制度的扩展。(C)2015 AIP Publishing LLC.
This study presents the effective tuning of perpendicular magnetic anisotropy in CoFeB/MgO thin films by He+ ion irradiation and its effect on domain wall motion in a low field regime. Magnetic anisotropy and saturation magnetisation are found to decrease as a function of the irradiation dose which can be related to the observed irradiation-induced changes in stoichiometry at the CoFeB/MgO interface. These changes in the magnetic intrinsic properties of the film are reflected in the domain wall dynamics at low magnetic fields (H) where irradiation is found to induce a significant decrease in domain wall velocity (v). For all irradiation doses, domain wall velocities at low fields are well described by a creep law, where Ln(v) vs. H-1/4 behaves linearly, up to a maximum field H*, which has been considered as an approximation to the value of the depinning field H-dep. In turn, H* approximate to H-dep is seen to increase as a function of the irradiation dose, indicating an irradiation-induced extension of the creep regime of domain wall motion. (C) 2015 AIP Publishing LLC.