Electrodeposition of ReMo alloys

The electrodeposition of superconducting ReMo alloys is investigated using highly concentrated electrolytes with acetate, citrate, and the two oxometallate anions, MoO4 2-and ReO4 -. The effects of applied deposition current, the concentrations of acetate, citrate, and metal source in the electrolyte on the film composition, faraday efficiency as well as the partial current densities of Re and Mo are systematically studied. A hybrid complex species, such as (MoO4 2-)(ReO4 -)(HCit3- )2 and its partially reduced form, is proposed to form and mediate the co-deposition reaction. The morphology and superconductivity of alloy films are characterized using microscopy and cryogenic four-probe measurements. The electrodeposited ReMo alloy films maintain the same amorphous grain structure and the same enhanced superconducting transition temperature as pure Re films.