STRUCTURE OF ELECTROLESS SILVER COATINGS OBTAINED USING COBALT(II) ASREDUCING AGENT

Scanning electron microscopic and X-ray diffraction investigations of silver coatings obtained from new solutions for electroless silver pla ting, where Co(II) complexes with ammonia serve as the reducing agent, were carried out. The structural characteristics of these coatings an d electrodeposited coatings were compared. The morphology of silver co atings deposited by the electroless method is more complicated in comp arison with that of coatings electroplated from similar solutions cont aining no reducing agent. The effects of inhibition of free growth of silver crystals are observed in the process of electroless silver depo sition caused, presumably, by the adsorption of cobalt compounds. The silver coatings have a rather perfect internal structure. Electroless silver coatings contain 0.005-0.05 mass% Co, presumably in the form of cobalt compounds.