Abstract Voltage control magnetism is one of the most energy efficient pathway towards magnetoelectric (ME) device. Ionic liquid gating (ILG) method has already shown impressive manipulation power at the IL/electrode interface to influence the structure, orbital as well as spin of the electrode materials. As key material in anisotropy magnetoresistance sensor and spin valve heterostructure, the permalloy Ni0.81Fe0.19 was utilized as the electrode to investigate the ILG induced magnetic anisotropy change. In this work, we realized magnetic anisotropy control in Au/[DEME]+[TFSI]-/Ni0.81Fe0.19 (2.5 nm)/Ta heterostructure via ILG caused electrostatic doping. This is evidenced in situ reversible ferromagnetic field (Hr) shift with electron spin resonance (ESR) spectrometer. Aiming at the question whether the charge accumulation at the ionic liquid interface is the main control mechanism at low voltage, we carefully tested the relationship between the change of resonance field and the amount of surface charge. It was found that these two had a good linear relationship between −1 V and +1 V. Defining the linear parameter as A whose value is 28.7 mT m2/Col. Unlike previously reported chemical regulation of Co, this article used ionic liquids to physically regulate NiFe, which has not been studied in the previous ionic liquid regulation. And NiFe has a narrower resonance line width for easy reference to microwave devices. In addition, It also has a stronger ferromagnetic signal than Co, which can be more easily detected as a sensor device. Therefore, this system is more promising. The ILG control NiFe may lead to a new kind of magnetoelectric sensor devices and path a new way to low energy consumption spintronics.

中文翻译：

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Ni0.81Fe0.19薄膜中磁各向异性的离子液体门控控制

摘要 电压控制磁性是实现磁电 (ME) 器件最节能的途径之一。离子液体门控 (ILG) 方法已经在 IL/电极界面显示出令人印象深刻的操纵能力，以影响电极材料的结构、轨道和自旋。作为各向异性磁阻传感器和自旋阀异质结构的关键材料，坡莫合金 Ni0.81Fe0.19 被用作电极来研究 ILG 引起的磁各向异性变化。在这项工作中，我们通过 ILG 引起的静电掺杂在 Au/[DEME]+[TFSI]-/Ni0.81Fe0.19 (2.5 nm)/Ta 异质结构中实现了磁各向异性控制。这在电子自旋共振 (ESR) 光谱仪的原位可逆铁磁场 (Hr) 位移中得到了证明。针对离子液体界面的电荷积累是否是低电压下的主要控制机制的问题，我们仔细测试了共振场的变化与表面电荷量之间的关系。发现这两者在-1 V和+1 V之间具有良好的线性关系。定义线性参数为A，其值为28.7 mT m2/Col。与之前报道的Co的化学调控不同，本文采用离子液体对NiFe进行物理调控，这在之前的离子液体调控中没有研究过。并且NiFe具有更窄的谐振线宽，便于微波器件参考。此外，它还具有比Co更强的铁磁信号，作为传感器设备更容易被检测到。因此，这个系统更有前途。