Ye Shujun, Shiokawa Yohei, Pati Satya Prakash, Sahashi Masashi
Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan.
ImPACT Program, Japan Science and Technology Agency, Tokyo 102-0076, Japan.
ACS Appl Mater Interfaces. 2020 Jul 1;12(26):29971-29978. doi: 10.1021/acsami.0c06210. Epub 2020 Jun 17.
Parasitic magnetism plays an important role in magnetoelectric spin switching of antiferromagnetic oxides, but its mechanism has not been clearly investigated. Unlike the widely obtained surface boundary magnetization in magnetoelectric CrO antiferromagnet, we previously reported that Al doping could produce volume-dependent parasitic magnetism () in CrO with the remaining magnetoelectric effect and antiferromagnetic properties. In this work, we systematically investigated the magnetic properties of in CrO through its different exchange coupling characteristics with the ferromagnet at various conditions. The columnar grain boundaries cause an antiferromagnetic sublattice breaking to produce uncompensated spins and thus are considered to be responsible for in both undoped and Al-doped CrO. Finally, a model was proposed for the formation mechanism of the parasitic magnetism in CrO, which explains the reported magnetic characteristics of CrO, and some current topics such as the domain formation and motion in CrO during magnetoelectric spin switching. This work contributes to a deep understanding of antiferromagnetic spintronics and provides a method to realize the low-energy operation of antiferromagnetic-based magnetic random access memory.
寄生磁性在反铁磁氧化物的磁电自旋切换中起着重要作用，但其机制尚未得到明确研究。与在磁电CrO反铁磁体中广泛获得的表面边界磁化不同，我们之前报道过，Al掺杂可在具有剩余磁电效应和反铁磁特性的CrO中产生与体积相关的寄生磁性（）。在这项工作中，我们通过在各种条件下与铁磁体的不同交换耦合特性，系统地研究了CrO中 的磁性。柱状晶界导致反铁磁亚晶格断裂，产生未补偿的自旋，因此被认为是未掺杂和Al掺杂的CrO中 产生的原因。最后，提出了一个关于CrO中寄生磁性形成机制的模型，该模型解释了所报道的CrO的磁性特征，以及一些当前的研究热点，如磁电自旋切换过程中CrO中的畴形成和运动。这项工作有助于深入理解反铁磁自旋电子学，并提供了一种实现基于反铁磁的磁性随机存取存储器低能量运行的方法。
