Large magnetoelectric effects are observed in as-sputtered (nanoparticulate-like) and electrochemically dealloyed (nanoporous) 200 nm thick Fe–Cu films. Application of positive voltages decreases both the saturation magnetization (M_S) and coercivity (H_C) of the films, while negative voltages cause the reverse effect (increase of M_S and H_C). The relative variations are as high as 20% for M_S and beyond 100% for H_C, both for the as-sputtered and dealloyed states. These changes in magnetic properties are caused by controlled and reversible electric-field-driven nanoscale phase transformations between face-centered cubic (fcc) and body-centered cubic (bcc) structures. These phase transitions are in turn due to selective redox reactions induced by the applied voltage, which can be regarded as a “magnetoionic effect.” The controlled tuning of H_C and M_S with the moderate values of applied voltage, together with the sustainable composition of the investigated alloys (not containing noble metals, as opposed to many previous works on magnetoelectric effects in thin films), pave the way towards the implementation of magnetic and spintronic devices with enhanced energy efficiency and functionalities.

中文翻译：

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溅射（纳米颗粒）和电化学脱合金（纳米多孔）Fe-Cu 薄膜中电场驱动的纳米级相变介导的大磁电效应†

在溅射（纳米颗粒状）和电化学脱合金（纳米多孔）200 nm 厚的 Fe-Cu 薄膜中观察到大磁电效应。施加正电压会降低薄膜的饱和磁化强度（M _S）和矫顽力（H _C ），而负电压会产生相反的效果（ M _S和H _C增加）。对于溅射状态和脱合金状态，MS的相对变化高达 20% ， H _{C的相对变化}超过 100% 。这些磁性变化是由面心立方 ( fcc ) 和体心立方 ( bcc ) 结构之间受控且可逆的电场驱动的纳米级相变引起的。这些相变又是由于施加电压引起的选择性氧化还原反应，这可以被视为“磁离子效应”。通过施加适中的电压值来控制 H C 和 M S 的调节，以及所研究合金的可持续成分（不包含贵金属，这与之前许多关于薄膜磁电效应的研究相反），为实现这一目标_铺平了道路_。实现具有增强能源效率和功能的磁性和自旋电子器件。