The en-riched ⁵⁸Ni powders are dissolved in acid solution and coated on a Cu target for proton irradiation at cyclotron to produce ⁵⁷Co radioisotope. The condition of the plating bath and the coating process are determined using the en-riched powders. To establish the coating conditions for ⁵⁷Co, non-radioactive Co ions are dissolved in an acid solution and electroplated on to a rhodium plate. The thermal diffusion of electroplated Co into a rhodium matrix was studied to apply a ⁵⁷Co Mssbauer source. The diffusion depth from surface to matrix of Co is depended on the annealing temperature and time. The deposited Co atoms diffuse completely into a rhodium (Rh) matrix without substantial loss at an annealing temperature of 1200 for 4 hours.