Electrical Switching of Magnetization in the Artificial Multiferroic CoFeB/BaTiO3
Electrical Switching of Magnetization in the Artificial Multiferroic CoFeB/BaTiO3
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DOI：
10.1002/aelm.201600085
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发表时间：
2016-07-01
影响因子：
6.2
通讯作者：
Bertacco, Riccardo
中科院分区：
文献类型：
--
作者：
Baldrati, Lorenzo;Rinaldi, Christian;Bertacco, Riccardo
鉴于金属/氧化物异质结构在新型固态器件中的应用，金属/氧化物异质结构中发生的电子、磁性、化学和机械现象最近受到了极大的关注。特别地，人造多铁性，即，由铁磁相和铁电相制成的层状或复合系统具有实现自旋电子器件中磁化的电控制的潜力。本文报道了一种新型的具有垂直磁各向异性的人工多铁性材料：CoFeB/BaTiO_3双层膜。在室温下，CoFeB磁矫顽场显示滞后行为，作为跨BaTiO 3层的电压的函数，对于铁电BaTiO 3极化的完全反转具有60%的变化。这被利用来实现在均匀的偏磁场下各个CoFeB电极的磁化的电切换。在局部BaTiO 3极化反转时，CoFeB电极从初始亚稳态跳跃到相反的稳定磁化状态，具有由磁粘度确定的特征切换时间。证明了磁辅助双极电开关的磁化，通过电压脉冲与互补金属氧化物半导体（CMOS）电子兼容，在均匀的偏置场低至10 Oe。
Electronic, magnetic, chemical, and mechanical phenomena occurring in metal/oxide heterostructures have recently received great attention in view of their exploitation in novel solid state devices. In particular, artificial multiferroics, i.e., layered or composite systems made of a ferromagnetic and ferroelectric phase, hold potential for achieving the electric control of the magnetization in spintronic devices. In this paper, a novel artificial multiferroic displaying perpendicular magnetic anisotropy is reported: the CoFeB/BaTiO3 bilayer. At room temperature, the CoFeB magnetic coercive field displays a hysteretic behavior, as a function of the voltage across the BaTiO3 layer, with a 60% variation for complete reversal of the ferroelectric BaTiO3 polarization. This is exploited to achieve the electric switching of the magnetization of individual CoFeB electrodes under a uniform magnetic bias field. Upon the local BaTiO3 polarization reversal, the CoFeB electrode jumps from an initial metastable state into the opposite stable magnetization state, with a characteristic switching time determined by magnetic viscosity. The magnetically assisted bipolar electric switching of the magnetization is demonstrated, via voltage pulses compatible with complementary metal-oxide semiconductor (CMOS) electronics, under uniform bias fields as low as 10 Oe.