Electric field control of magnetization direction across the antiferromagnetic to ferromagnetic transition

• Published in: Scientific reports Vol. 7; no. 1; pp. 5366 - 9
• Main Authors: Zheng, Guohui, Ke, San-Huang, Miao, Maosheng, Kim, Jinwoong, Ramesh, R., Kioussis, Nicholas
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 14-07-2017; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 142/136; 639/766/119/1001; 639/766/119/997; Anisotropy; Electric fields; Humanities and Social Sciences; Magnetism; MATERIALS SCIENCE; multidisciplinary; Random access memory; Science; Science & Technology - Other Topics; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-05611-7

Electric-field-induced magnetic switching can lead to a new paradigm of ultra-low power nonvolatile magnetoelectric random access memory (MeRAM). To date the realization of MeRAM relies primarily on ferromagnetic (FM) based heterostructures which exhibit low voltage-controlled magnetic anisotropy (VCMA) efficiency. On the other hand, manipulation of magnetism in antiferromagnetic (AFM) based nanojunctions by purely electric field means (rather than E-field induced strain) remains unexplored thus far.
Ab initio
electronic structure calculations reveal that the VCMA of ultrathin FeRh/MgO bilayers exhibits distinct linear or nonlinear behavior across the AFM to FM metamagnetic transition depending on the Fe- or Rh-interface termination. We predict that the AFM Fe-terminated phase undergoes an E-field magnetization switching with large VCMA efficiency and a
spin reorientation
across the metamagnetic transition. In sharp contrast, while the Rh-terminated interface exhibits large out-of-plane (in-plane) MA in the FM (AFM) phase, its magnetization is more rigid to external E-field. These findings demonstrate that manipulation of the AFM Néel-order magnetization direction via purely E-field means can pave the way toward ultra-low energy
AFM-based
MeRAM devices.