Composition for electroplating palladium alloys and electroplating process using that composition

An aqueous palladium alloy electroplating bath consisting of:

• a metal consisting essentially of a palladium salt having a palladium electroplating reduction potential and an alloying metal salt selected from the group consisting of cobalt salts and iron salts having an alloying metal electroplating reduction potential, and
• a mixed ligand system, said mixed ligand system comprising a first ligand selected from the group consisting of ammonia, amines, diamines, polyamines and their derivatives, said first ligand present in amount effective to form a complex with said palladium salt and a second ligand selected from the group consisting of an acetate, a citrate, malonic acid, glutaric acid, citric acid, tartaric acid, oxalic acid, ethylenediamine, glycine and ethylenediaminetetraacetate, said second ligand present in an amount effective to form a complex with said alloying metal salt to bring said alloying metal electroplating reduction potential in a negative, less anodic, direction relative to said alloying metal electroplating reduction potential in the presence of said first ligand alone.