The Research On The Electrodeposition Of Fe-Nd-P Alloy Films And Fe-Ce-P Alloy Films In Aqueous Solutions

Thin films of rare earths have been applied widely in magnetic, optical, electrolytic and superconductor devices, and aroused many material researchers' interests.In this paper, the properties and application of rare earth are summarized. Theory and possibilities for electrodeposition of rare earth metals and their alloys from aqueous solutions are discussed.The electrodeposition of Fe-Nd-P and Fe-Ce-P alloy films in aqueous solution was studied. The black films with a thickness up to 5m of Fe-Nd-P and Fe-Ce-P alloys were successfully prepared on copper substrate by electrodeposition from aqueous bath. The role bath components include NdCl3(or CeCl3), FeCl2, H3PO3, Cit and NH4C1. The reduction potential of rare earth shifted positively due to the complexing agent (formed with citric acid) and the copper substrate, which made rare earth alloy films deposition possible. The effects of the concentration ratio of metallic salt, complexing agent, pH value, bath temperature and plating time on deposition rate and composition are studied. Proper technological parameters were obtained for the realization of the codeposition of Fe-Nd-P alloys with high Nd content and fine quality. The appearance of alloy films was analyzed by scanning electron microscopy(SEM).The result shows that the surface of alloy films is smooth.In addition, the effects of alloy composition and heat treatment temperature on the microhardness of alloy films were studied in this paper. The results of the microhardness of films show that the rare earth alloy films have higher hardness than Cu substrate material. Fe-Nd-P alloy films and Fe-Ce-P alloy films which own high Ce content have higher hardness than rare earth-free Fe-P alloy films. After heat treating from 300 C to 600 C , hardness of rare earth alloy films decreases with the increase of annealing temperature.Magnetic behaviors of Fe-Nd-P and Fe-Ce-P alloy films are studied. Magnetic measurements show that the saturate intensity of magnetization , remanence and coercive force of these alloy films are higher than those of the rare earth-free Fe-P alloy films.