Abeed Md Ahsanul, Atulasimha Jayasimha, Bandyopadhyay Supriyo
Department of Electrical and Computer Engineering, Virginia Commonwealth University, Richmond, VA 23284, United States of America.
J Phys Condens Matter. 2018 Oct 3;30(39):394001. doi: 10.1088/1361-648X/aadb6a. Epub 2018 Aug 20.
We theoretically study the effect of a material defect (material void) on switching errors associated with magneto-elastic switching of magnetization in elliptical magnetostrictive nanomagnets having in-plane magnetic anisotropy. We find that the error probability increases significantly in the presence of the defect, indicating that magneto-elastic switching is particularly vulnerable to material imperfections. Curiously, there is a critical stress value that gives the lowest error probability in both defect-free and defective nanomagnets. The critical stress is much higher in defective nanomagnets than in defect-free ones. Since it is more difficult to generate the critical stress in small nanomagnets than in large nanomagnets (having the same energy barrier for thermal stability), it would be a challenge to downscale magneto-elastically switched nanomagnets in memory and other applications where reliable switching is required. This is likely to be further exacerbated by the presence of defects.
我们从理论上研究了材料缺陷（材料空洞）对具有面内磁各向异性的椭圆形磁致伸缩纳米磁体中与磁化的磁弹性开关相关的开关误差的影响。我们发现，在存在缺陷的情况下，误差概率会显著增加，这表明磁弹性开关对材料缺陷特别敏感。奇怪的是，存在一个临界应力值，在无缺陷和有缺陷的纳米磁体中都能给出最低的误差概率。有缺陷的纳米磁体中的临界应力比无缺陷的纳米磁体中的临界应力高得多。由于在小纳米磁体中产生临界应力比在大纳米磁体中更困难（对于热稳定性具有相同的能垒），在需要可靠开关的存储器和其他应用中缩小磁弹性开关纳米磁体的尺寸将是一个挑战。缺陷的存在可能会进一步加剧这种情况。
