Microstructure and magnetic behavior of electrodeposited CoPt thick films upon annealing

CoPt films with a thickness about 5-mu m consisting of a disordered face-centered cubic phase have been prepared by using the electrodeposition technique. X-ray diffraction measurements and transmission electron microscopy studies reveal that the annealed CoPt films possess a nanocomposite microstructure of A1 + L1(0) CoPt and the size and volume fraction of the L1(0) ordered phase increase with annealing time. A strong magnetic exchange coupling between the A1 phase and the L1(0) ordered phase is observed after annealing for 2.5 h, which yields a large coercivity H-c = 14.2 kOe and a high remanence ratio M-r/M-s = 0.88 for the nanocomposite thick films of A1 + L1(0) CoPt. (c) 2007 Elsevier B.V. All rights reserved.