Scaling dependence and tailoring of the pinning field in FePt-based exchange coupled composite media
Scaling dependence and tailoring of the pinning field in FePt-based exchange coupled composite media
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DOI：
10.1088/0957-4484/25/4/045604
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发表时间：
2014-01
期刊：
影响因子：
3.5
通讯作者：
Jehyun Lee;D. Makarov;C. Brombacher;B. Dymerska;D. Suess;M. Albrecht;J. Fidler
中科院分区：
文献类型：
--
作者：
Jehyun Lee;D. Makarov;C. Brombacher;B. Dymerska;D. Suess;M. Albrecht;J. Fidler
研究了由硬磁L10化学有序FePtCu合金膜和磁性较软的[Co/Pt]N多层膜组成的易轴面外的交换耦合复合（ECC）介质。通过调整FePtCu合金和[Co/Pt]N多层膜的结构特性，可以在很宽的范围内调节复合材料的磁参数。这使我们能够通过实验解决决定ECC介质性能的最关键属性之一，即硬层和软层之间界面处存在的磁畴壁的钉扎场。我们证明了钉扎场与硬层和软层的磁各向异性常数之差成正比，这证实了理论预测。此外，我们表明，钉扎场可以有效地减少后，额外的退火步骤。透射电子显微镜的调查表明，所观察到的效果的起源是由于在硬层和软层之间的界面处存在的铁氧化物的热诱导相变。这项研究表明，定制的硬/软接口的属性是另一个有效的调谐旋钮的ECC媒体的性能优化。
We studied exchange coupled composite (ECC) media with an out-of-plane easy axis consisting of hard magnetic L10 chemically ordered FePtCu alloy films and magnetically softer [Co/Pt]N multilayer stacks. By tailoring the structural properties of the ternary FePtCu alloy and [Co/Pt]N multilayers, we can tune the magnetic parameters of the composite in a wide range. This allowed us to address experimentally one of the most crucial properties determining the performance of ECC media, namely the pinning field of the magnetic domain wall present at the interface between the hard and soft layers. We demonstrate that the pinning field is proportional to the difference of the magnetic anisotropy constants of the hard and soft layers, which confirms the theoretical predictions. Furthermore, we show that the pinning field can be efficiently decreased after an additional annealing step. Transmission electron microscopy investigations indicated that the origin of the observed effect is due to a heat-induced phase transformation of iron oxide present at the interface between the hard and soft layers. This study reveals that tailoring the properties of the hard/soft interface is another efficient tuning knob for optimization of the performance of ECC media.