Electromechanical behaviour of nanoporous metallic glass

Understanding the electrical and mechanical behaviour of nanoporous materials is critical for their use in energy applications. A palladium-rich nanoporous film, 500 nm thick with pore size ranging from 10 to 50 nm, was obtained by electrochemical dealloying of a Ni–Pd–P–B metallic glass. Nanomechanical and electrical properties were measured simultaneously, as a function of depth, for the nanoporous structure as well as the unaltered metallic glass substrate. The elastic modulus for the nanoporous structure was found to be 22 GPa compared to 131 GPa for the metallic glass substrate. The ratio of moduli scales with the square of the relative density in agreement with linear elasticity models for cellular materials. The electrical resistivity of the nanoporous layer was found to be 2.2 times higher compared to the metallic glass substrate, which was attributed to the tortuosity of current path in cellular structures.