Conformal oxide nanocoatings on electrodeposited 3D porous Ni films by atomic layer deposition

Abstract

A versatile chemical synthesis procedure to obtain Al₂O₃ and Co₂FeO₄ nanolayers conformally coating a three-dimensional (3D) porous Ni film is presented. First, porous Ni is grown by hydrogen bubble template-assisted electrodeposition. Subsequently, Al₂O₃ and Co₂FeO₄ layers, with thickness ranging from 5 nm to 25 nm, are directly deposited onto the pore walls by atomic layer deposition, while maintaining the porous architecture and magnetic properties of the Ni scaffold. The crystal structure, thickness and distribution of elements within the composite coatings are investigated in detail. The resulting magnetic and wettability properties are assessed. Contact angle tests reveal that 3D porous Ni films become more hydrophilic after coating with Al₂O₃ or Co₂FeO₄. From a technological point of view, the obtained composite porous films could be appealing for application in magnetically actuated micro/nano-electromechanical systems (MEMS/NEMS) or bio-MEMS/NEMS, among others.