Analytic theory for the switch from Bloch to Neel domain wall in nanowires with perpendicular anisotropy
Analytic theory for the switch from Bloch to Neel domain wall in nanowires with perpendicular anisotropy
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DOI：
10.1103/physrevb.92.214420
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发表时间：
2015-12-14
影响因子：
3.7
通讯作者：
Livesey, K. L.
中科院分区：
文献类型：
--
作者：
DeJong, M. D.;Livesey, K. L.
矩形纳米线可以具有成核的畴壁并移动穿过它们以实现许多器件。已经表明，在具有垂直各向异性的纳米线的特定宽度和厚度下，存在从布洛赫型畴壁到尼尔型畴壁的转变。这个临界形状可以通过微磁学模拟找到，但在这里我们提出了两种壁类型能量的分析计算，涉及退磁能量密度的近似值。所实现的近似包括磁化的一维模型和简化的初始磁化配置，由此通过迭代过程求解退磁能量密度。所开发的表达式很长，但优点是只需输入磁性材料的材料参数，即可使用计算器在几秒钟内找到关键形状。我们将我们的结果与使用微磁学发现的结果和通过实验发现的结果进行比较，结果吻合良好。
Rectangular nanowires may have domain walls nucleated and moved through them to realize many devices. It has been shown that at a particular width and thickness of a nanowire with perpendicular anisotropy, there is a switch from the domain wall being of Bloch-type to it being of Neel-type. This critical shape can be found through micromagnetics simulations, but here we present an analytic calculation for the energies of both wall types involving approximations for the demagnetizing energy density. The approximations implemented include a one-dimensional model of the magnetization and a simplified initial magnetization configuration whereby the demagnetizing energy density is solved through an iterative process. The expressions developed are long, but have the advantage that by simply inputting material parameters for the magnetic material, the critical shape can be found using a calculator in a matter of seconds. We compare our results to those found using micromagnetics and those found experimentally and the agreement is good.