The effects of interfacial exchange coupling in Fe/ErFeO 3 heterostructures

作者：Jin Tang, Ya-Jiao Ke, Wei He, X Q Zhang, Yuqing Zhang, W Zhang, Yan Li, S.Sheraz Ahmad, Zhao‐Hua Cheng · 发表于：Journal of Physics D Applied Physics · 年份：2017 · DOI：10.1088/1361-6463/aa69e1 · 被引用次数：3 · 研究领域：Magnetic properties of thin films、Multiferroics and related materials、Magnetic and transport properties of perovskites and related materials

Abstract Exploring exchange bias in ferromagnetic (FM)/antiferromagnetic (AFM) heterostructures is vital for both fundamental magnetism and practical application. However, in the case of conventional FM/AFM systems, the essential field cooling process above the Néel temperature of AFM materials hinders their application if the Néel temperature is far higher than room-temperature. Here, we report the effects of interfacial exchange coupling in Fe/ErFeO 3 heterostructures. The magnetic-field-induced switchable exchange bias, originating from the AFM exchange coupling between Fe film and Dzyaloshinskii–Moriya-interaction-induced net moment of ErFeO 3 along c axis, is successfully achieved without field cooling or in-field growth process of AFM. Different from the most previous pinning layer using a hard FM or traditional AFM, ErFeO 3 pinning layer has the advantages of both the magnetic field sensitivity (~780 Oe) and ultrahigh dynamic frequency. In addition, although Fe film is polycrystalline, it exhibits a strong uniaxial magnetic anisotropy resulted from the so-called ‘spin-flop-coupling effect’, i.e. the magnetic coupling between Fe film and the compensated G -type AFM spins of EFO along a axis. Interestingly, the exchange bias field and asymmetric switching field offer entirely different information about the asymmetry of magnetization reversal near hard axis. The asymmetric switching field is further proved to be an effective measure to determine the weak unidirectional m...