The effects of interfacial exchange coupling in Fe/ErFeO3 heterostructures
The effects of interfacial exchange coupling in Fe/ErFeO3 heterostructures
复制标题
Fe/ErFeO3 异质结构中界面交换耦合的影响
DOI：
10.1088/1361-6463/aa69e1
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发表时间：
2017
影响因子：
3.4
通讯作者：
Cheng Z. H.
中科院分区：
文献类型：
--
作者：
Tang J.;Ke Y. J.;He W.;Zhang X. Q.;Zhang Y. S.;Zhang W.;Li Y.;Ahmad S. S.;Cheng Z. H.
研究铁磁/反铁磁异质结构中的交换偏置对磁学基础和实际应用都具有重要意义。然而，在常规FM/AFM系统的情况下，如果Néel温度远高于室温，则AFM材料的Néel温度以上的基本场冷却过程阻碍了它们的应用。本文报道了Fe/ErFeO 3异质结构中界面交换耦合效应。磁场感应开关交换偏置是由Fe薄膜与ErFeO 3沿着c轴的Dzyaloshinskiii-Moriya相互作用感应净磁矩之间的AFM交换耦合产生的，无需AFM的场冷却或场内生长过程。与以往大多数使用硬FM或传统AFM的钉扎层不同，ErFeO 3钉扎层具有磁场灵敏度（~ 780 Oe）和动态频率低的优点。此外，Fe膜虽然是多晶的，但它表现出很强的单轴磁各向异性，这是由所谓的“自旋翻转耦合效应”（spin-flop-coupling effect）引起的，即Fe膜与EFO的补偿后的G型AFM自旋沿着轴向的磁耦合。有趣的是，交换偏置场和非对称开关场提供了关于难磁化轴附近磁化反转的非对称性的完全不同的信息。进一步证明了非对称翻转场是确定畴壁位移接近180的薄膜弱单向磁各向异性的有效手段。我们的实验结果提供了一个实用的方法来建立室温交换偏置FM/G型原子力显微镜没有场冷却。此外，Fe/ErFeO 3异质结构中磁场诱导的可切换交换偏置、自旋翻转耦合效应以及难磁化轴附近磁化反转的角度依赖不对称性，为FM/AFM系统中界面交换耦合提供了新的认识.
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', ie 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 magnetic anisotropy for film with nearly 180 domain wall displacement. Our experimental results provide a practical method to establish room-temperature exchange bias in FM/G-type AFM without field cooling. Furthermore, the magnetic-field-induced switchable exchange-bias, the spin-flop coupling effect and the angular dependent asymmetry of magnetization reversal in the vicinity of hard axis in Fe/ErFeO 3 heterostructures may provide new insights on the interfacial exchange coupling in FM/AFM systems.