Detzmeier Joscha, Königer Kevin, Blachowicz Tomasz, Ehrmann Andrea
Faculty of Engineering and Mathematics, Bielefeld University of Applied Sciences, 33619 Bielefeld, Germany.
Center for Science and Education, Institute of Physics, Silesian University of Technology, 44-100 Gliwice, Poland.
Nanomaterials (Basel). 2021 Mar 21;11(3):800. doi: 10.3390/nano11030800.
Horizontally shifted and asymmetric hysteresis loops are often associated with exchange-biased samples, consisting of a ferromagnet exchange coupled with an antiferromagnet. In purely ferromagnetic samples, such effects can occur due to undetected minor loops or thermal effects. Simulations of ferromagnetic nanostructures at zero temperature with sufficiently large saturation fields should not lead to such asymmetries. Here we report on micromagnetic simulations at zero temperature, performed on sputtered nanoparticles with different structures. The small deviations of the systems due to random anisotropy orientations in the different grains can not only result in strong deviations of magnetization reversal processes and hysteresis loops, but also lead to distinctly asymmetric, horizontally shifted hysteresis loops in purely ferromagnetic nanoparticles.
水平移动且不对称的磁滞回线通常与交换偏置样品相关联，这些样品由与反铁磁体交换耦合的铁磁体组成。在纯铁磁样品中，由于未检测到的小磁滞回线或热效应，可能会出现这种效应。在零温度下对具有足够大饱和场的铁磁纳米结构进行模拟不应导致这种不对称性。在这里，我们报告了在零温度下对具有不同结构的溅射纳米颗粒进行的微磁模拟。由于不同晶粒中随机各向异性取向导致的系统小偏差，不仅会导致磁化反转过程和磁滞回线的强烈偏差，还会在纯铁磁纳米颗粒中导致明显不对称、水平移动的磁滞回线。
