Anomalous switching pattern in the ferrimagnetic memory cell

IF 2.5 3区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Magnetism and Magnetic Materials Pub Date : 2024-11-02 DOI:10.1016/j.jmmm.2024.172614

Zhuo Xu , Zhengping Yuan , Xue Zhang , Zhengde Xu , Yixiao Qiao , Yumeng Yang , Zhifeng Zhu

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引用次数: 0

Abstract

Replacing the ferromagnet with ferrimagnet (FiM) in the magnetic tunnel junction (MTJ) allows faster magnetization switching in picoseconds. The operation of a memory cell that consists of the MTJ and a transistor requires reversable magnetization switching. When a constant voltage is applied, we find that the spin-transfer torque can only switch the FiM-MTJ from parallel to antiparallel state. This stems from the small switching window of FiM and the dynamic resistance variation during the magnetization switching. We find the resulting current variation can be suppressed by reducing the magnetoresistance ratio. Furthermore, we demonstrate that the switching window can be expanded by adjusting the amount of Gd in FiM. We predict that the polarity of both switching current (J_c,switch) and oscillation current (J_c,osc) reverses at the angular momentum compensation point but not the magnetization compensation point. This anomalous dynamic behavior is attributed to the different physical nature of magnetization switching and oscillation in FiM, which must be considered when designing FiM-based MRAM.

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铁磁记忆单元中的异常开关模式

在磁隧道结（MTJ）中用铁磁体（FiM）取代铁磁体，可以在皮秒级的时间内实现更快的磁化切换。由 MTJ 和晶体管组成的存储单元的运行需要可逆的磁化切换。当施加恒定电压时，我们发现自旋转移力矩只能将 FiM-MTJ 从平行状态切换到反平行状态。这是因为 FiM 的开关窗口较小，而且在磁化切换过程中存在动态电阻变化。我们发现可以通过降低磁阻比来抑制由此产生的电流变化。此外，我们还证明可以通过调整 FiM 中的钆含量来扩大开关窗口。我们预测开关电流（Jc,switch）和振荡电流（Jc,osc）的极性在角动量补偿点会反转，但在磁化补偿点不会。这种反常的动态行为归因于 FiM 中磁化开关和振荡的不同物理特性，在设计基于 FiM 的 MRAM 时必须考虑到这一点。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Magnetism and Magnetic Materials 物理-材料科学：综合

CiteScore

5.30

自引率

11.10%

发文量

1149

审稿时长

59 days

期刊介绍： The Journal of Magnetism and Magnetic Materials provides an important forum for the disclosure and discussion of original contributions covering the whole spectrum of topics, from basic magnetism to the technology and applications of magnetic materials. The journal encourages greater interaction between the basic and applied sub-disciplines of magnetism with comprehensive review articles, in addition to full-length contributions. In addition, other categories of contributions are welcome, including Critical Focused issues, Current Perspectives and Outreach to the General Public. Main Categories: Full-length articles: Technically original research documents that report results of value to the communities that comprise the journal audience. The link between chemical, structural and microstructural properties on the one hand and magnetic properties on the other hand are encouraged. In addition to general topics covering all areas of magnetism and magnetic materials, the full-length articles also include three sub-sections, focusing on Nanomagnetism, Spintronics and Applications. The sub-section on Nanomagnetism contains articles on magnetic nanoparticles, nanowires, thin films, 2D materials and other nanoscale magnetic materials and their applications. The sub-section on Spintronics contains articles on magnetoresistance, magnetoimpedance, magneto-optical phenomena, Micro-Electro-Mechanical Systems (MEMS), and other topics related to spin current control and magneto-transport phenomena. The sub-section on Applications display papers that focus on applications of magnetic materials. The applications need to show a connection to magnetism. Review articles: Review articles organize, clarify, and summarize existing major works in the areas covered by the Journal and provide comprehensive citations to the full spectrum of relevant literature.