Open AccessCoercivity Modulation in Fe–Cu Pseudo‐Ordered Porous Thin Films Controlled by an Applied Voltage: A Sustainable, Energy‐Efficient Approach to Magnetoelectrically Driven Materials
Author(s) -
Dislaki Evangelia,
Robbennolt Shauna,
CampoyQuiles Mariano,
Nogués Josep,
Pellicer Eva,
Sort Jordi
Publication year - 2018
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201800499
Subject(s) - materials science , coercivity , porosity , electrolyte , voltage , electric field , composite material , polystyrene , voltage reduction , electrode , condensed matter physics , chemistry , physics , quantum mechanics , polymer
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.