Influence of stress and texture on soft magnetic properties of thin films
Influence of stress and texture on soft magnetic properties of thin films
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DOI：
10.1109/tmag.2002.802705
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发表时间：
2002-12
影响因子：
2.1
通讯作者：
Pei Zou;W. Yu;J. Bain
中科院分区：
文献类型：
--
作者：
Pei Zou;W. Yu;J. Bain
本文介绍了薄膜的应力、晶体学织构和软磁性能之间的关系。所考虑的磁性能是那些受条纹域的形成和磁化涟漪的形成。在实践中，这两种不期望的磁畴结构中的一种几乎总是改善软磁性能的障碍。理论分析占的贡献，从应力通过磁致伸缩各向异性，并计算所得到的总的，应力依赖的各向异性的膜。然后分析该各向异性以产生有效垂直和局部面内各向异性常数。这些常数允许通过村山的条纹畴理论计算条纹畴开始厚度，并通过霍夫曼的涟漪理论计算涟漪矫顽磁力。对溅射CoFe和FeAlN薄膜这两种最有前途和广泛研究的高密度记录磁头极材料的例子，从理论上计算和实验上验证了应力和织构对条纹畴起始厚度和涟漪介电常数的影响。结果表明，应力和软磁性能之间的相互作用取决于详细的成分，生长织构，生长形态（无论是在柱状时尚或等轴微晶生长的薄膜），晶粒尺寸，和厚度的薄膜正在考虑。在这些结果的基础上，本文提供了一个系统的方法来选择适当的组合物，纹理和厚度，使低应力同时促进磁状态中的条纹域被抑制和矫顽力低。这里提出的计算可以很容易地扩展到其他方面的软磁性的涟漪理论，如初始磁导率。
This paper presents the relationship among stress, crystallographic texture, and soft magnetic properties of thin films. The magnetic properties considered are those affected by the formation of stripe domains and by the formation of magnetization ripple. In practice, one of these two undesirable domain structures is almost always the impediment to improving the soft magnetic properties. The theoretical analysis accounts for the contribution from stress through magnetostrictive anisotropy, and calculates the resulting total, stress-dependent anisotropy of the film. This anisotropy is then analyzed to yield the effective perpendicular and local in-plane anisotropy constants. These constants allow the calculation of the stripe domain onset thickness through Murayama's stripe domain theory, and the ripple coercivity through Hoffmann's ripple theory. The influence of stress and texture on the stripe domain onset thickness and ripple coercivity is theoretically calculated and experimentally verified for the examples of sputtered CoFe and FeAlN films, two of the most promising and widely studied materials for high-density recording head poles. The results indicate that the interactions between stress and soft magnetic properties depend on the details of composition, growth texture, growth morphology (whether the film is grown in columnar fashion or as equiaxial crystallites), grain size, and thickness of the film under consideration. On the basis of these results, the paper offers a systematic approach to choosing the appropriate composition, texture, and thickness so that low stresses simultaneously promote magnetic states in which stripe domains are suppressed and coercivities are low. The calculations presented here can be easily extended to other aspects of soft magnetic properties addressed by the ripple theory, such as initial permeability.