Hierarchical structure and the origins of coercivity in exchange-coupled Co-Pt nanochessboards
Hierarchical structure and the origins of coercivity in exchange-coupled Co-Pt nanochessboards
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DOI：
10.1016/j.jmmm.2019.165313
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发表时间：
2019-10-01
影响因子：
2.7
通讯作者：
Soffa, W. A.
中科院分区：
文献类型：
--
作者：
Floro, J. A.;Vetter, E. P.;Soffa, W. A.
我们报告了第一个详细的调查如何交换耦合的磁性演变过程中形成的Co-Pt L1（0）+ L1（2）nanochessboards，自组装的伪旋节机制低于共析等温线。观察到的最大磁化率超过3 kOe，但这些值比理想的单菌落棋盘微磁学模拟预测的最大值低5倍以上。对于由成核控制的磁化反转，一个简单的分析很容易调和这种差异，占与多晶结构，存在于50 μ m的长度尺度，在0.5 μ m的长度尺度与共析殖民地相关的退磁场，和非理想的棋盘结构在约20 nm的归档长度尺度的取向不良。
We report the first detailed investigation into how exchange-coupled magnetic properties evolve during the formation of the Co-Pt L1(0) + L1(2) nanochessboards, which self-assemble by a pseudo-spinodal mechanism below the eutectoid isotherm. The maximum observed coercivities exceed 3 kOe, but these values are more than 5 times lower than the largest values predicted by micromagnetics simulations of ideal, single-colony chessboards. For magnetization reversal controlled by nucleation, a simple analysis readily reconciles this discrepancy by accounting for misorientation associated with the polycrystalline structure that exists at the 50 mu m lengthscale, demagnetizing fields associated with eutectoid colonies at the 0.5 mu m lengthscale, and non-idealities in the chessboard structure at the filing lengthscale of about 20 nm.