Extracting intergranular exchange coupling in perpendicular magnetic recording media
Extracting intergranular exchange coupling in perpendicular magnetic recording media
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DOI：
10.1016/j.jmmm.2010.12.021
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发表时间：
2012-02
影响因子：
2.7
通讯作者：
Yan Dong;R. Victora
中科院分区：
文献类型：
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作者：
Yan Dong;R. Victora
利用微磁数值技术证明了如何从测量两种类型的M-H曲线中提取晶间交换耦合和本征各向异性场色散。利用平面Voronoi细胞形成的真实颗粒结构来模拟垂直磁介质。该技术通过发现颗粒间交换耦合和各向异性色散与不同初始磁化状态下的微分M-H曲线的相关性，有效地分离了颗粒间交换耦合和各向异性色散的影响，即使存在热波动。通过一系列不同介质厚度的晶间交换耦合和各向异性色散实验，验证了该方法的有效性。证明了交流擦除样品的自相关函数与交换相互作用色散之间的关系。利用磁化自相关函数，磁晶间交换耦合统计量与自相关函数形状在零交叉和欠冲值方面具有相关性。
A micromagnetic numerical technique has been used to demonstrate how intergranular exchange coupling and intrinsic anisotropy field dispersion can be extracted from measuring two types of M–H curves. A realistic grain configuration formed by planar Voronoi cells is used to simulate perpendicular magnetic media. This technique effectively separates the effects of intergranular exchange coupling and anisotropy dispersion by finding their correlation to differentiated M–H curves with different initial magnetization states, even in the presence of thermal fluctuation. The validity of this method is investigated with a series of intergranular exchange couplings and anisotropy dispersions for different media thickness. A relationship between the auto-correlation function of an ac-erased sample and dispersion of the exchange interaction is demonstrated. Utilizing magnetization auto-correlation functions, the magnetic intergranular exchange coupling statistics show a correlation with the auto-correlation function shape in terms of zero-cross and undershoot values.