Near-equiatomic Co-Pt thin films with thicknesses of 520 nm were deposited from a single electrolyte onto glass-based Au-coated substrates using the electrodeposition method. The as-deposited Co-Pt-based films were annealed at temperatures from 500 degrees C to 700 degrees C for 1 h. The phase formation, microstructure and the magnetic properties were analyzed. It was found that with an increase of the annealing temperature the coercivity increases up to 1.18 T due to the transformation to the L1(0) phase. In contrast to the coercivity the saturation magnetization and the remanence were found to decrease upon annealing, due to the decrease of the Co concentration in the Co-Pt film because of the oxidation and the interdiffusion reactions between the Co-Pt thin film and the substrate. (C) 2009 Elsevier B.V. All rights reserved.