Effect of varying ferromagnetic anisotropy on exchange-bias in [Pt/Co]3/NiO(11 Å) multilayers
Effect of varying ferromagnetic anisotropy on exchange-bias in [Pt/Co]3/NiO(11 Å) multilayers
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DOI：
10.1016/j.jmmm.2004.04.110
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发表时间：
2004-10
影响因子：
2.7
通讯作者：
Z. Y. Liu
中科院分区：
文献类型：
--
作者：
Z. Y. Liu
研究了不同铁磁各向异性对[Pt（5A）/Co（tCo）]3/NiO（11 A）多层膜中交换偏置场、交换偏置场的温度依赖性和阻塞温度的影响.随着Co层厚度tCo的增加，铁磁易轴从面外切换到面内。分别沿面外和面内方向进行沿着场冷却后，观察到了一些有趣的特征。面内交换场远低于面外交换场，并在低得多的阻塞温度下趋于零。随着Co层厚度的增加，面内和面外阻塞温度都下降。面外交换场的温度依赖性表现为两个不同的区域，这两个区域由接近于tCo= 20 ℃时的面内阻挡温度TB= 35 K的温度TCr分开。交换场在两个区域中线性减小，但在TCr以下具有陡得多的斜率。这些特征被认为与界面NiO自旋结构随铁磁各向异性易轴的变化以及NiO各向异性的温度行为有关。
An investigation has been performed on the effect of varying ferromagnetic anisotropy on the exchange biasing field, its temperature dependence, and blocking temperature in [Pt(5 A ̊ )/Co( tCo)]3/NiO(11 A ̊ ) multilayers. The ferromagnetic easy axis switches from out-of-plane to in-plane on increasing the Co layer thickness tCo. After field cooling along out-of-plane and in-plane directions, respectively, a number of interesting features have been observed. The in-plane exchange field is much lower than the out-of-plane one, and goes to zero at a much lower blocking temperature. Both the in-plane and out-of-plane blocking temperatures drop with increasing Co layer thickness. The temperature dependence of the out-of-plane exchange field displays two distinct regions, which are separated by a temperature TCrclose to the in-plane blocking temperature TB=35K at tCo=20Å. The exchange field decreases linearly in both regions but with a much steeper slope below TCr. These features are considered to be related to the variation of interfacial NiO spin structures with the ferromagnetic anisotropy easy axis and the temperature behavior of the NiO anisotropies.