Fe–Cu films with pseudo‐ordered, hierarchical porosity are prepared by a simple, two‐step procedure that combines colloidal templating (using sub‐micrometer‐sized polystyrene spheres) with electrodeposition. The porosity degree of these films, estimated by ellipsometry measurements, is as high as 65%. The resulting magnetic properties can be controlled at room temperature using an applied electric field generated through an electric double layer in an anhydrous electrolyte. This material shows a remarkable 25% voltage‐driven coercivity reduction upon application of negative voltages, with excellent reversibility when a positive voltage is applied, and a short recovery time. The pronounced reduction of coercivity is mainly ascribed to electrostatic charge accumulation at the surface of the porous alloy, which occurs over a large fraction of the electrodeposited material due to its high surface‐area‐to‐volume ratio. The emergence of a hierarchical porosity is found to be crucial because it promotes the infiltration of the electrolyte into the structure of the film. The observed effects make this material a promising candidate to boost energy efficiency in magnetoelectrically actuated devices.

中文翻译：

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由施加电压控制的 Fe-Cu 伪有序多孔薄膜的矫顽力调制：一种可持续、节能的磁电驱动材料方法

具有伪有序、分级孔隙率的 Fe-Cu 薄膜是通过简单的两步程序制备的，该程序将胶体模板（使用亚微米尺寸的聚苯乙烯球）与电沉积相结合。通过椭圆光度测量估计，这些薄膜的孔隙率高达 65%。由此产生的磁性能可以在室温下使用通过无水电解质中的双电层产生的外加电场来控制。该材料在施加负电压时表现出显着的 25% 电压驱动矫顽力降低，在施加正电压时具有出色的可逆性，并且恢复时间短。矫顽力的显着降低主要归因于多孔合金表面的静电荷积累，由于其高表面积与体积比，这种现象发生在大部分电沉积材料上。人们发现分级孔隙率的出现至关重要，因为它促进电解质渗透到薄膜结构中。观察到的效应使这种材料成为提高磁电驱动设备能源效率的有希望的候选材料。