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

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 watts 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.