MAGNETIC MATERIALS RESEARCH
LEHIGH UNIV BETHLEHEM PA INST OF RESEARCH
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Several experiments in electroless deposition of thin Ni films were performed at room temperature and at 78C. Electroless deposition involves the reduction of a metal Ni compound by hydrophosphites in a heated solution. The solutions contained 30gl of NiCl2, 10gl of NaH2PO2, 50gl of NH4Cl, 100gl of sodium citrate, and NH4OH to a pH of 8 to 10. Substrates were commercially pure Al sheet, degreased and insulated on one side with spray lacquer. No deposits were obtained at room temperature and erratic results were obtained at 78C. When uninsulated Al sheet was used at 80 or - 3C, a minimum of 3 min was required to plate the entire Al surface with nickel. The Ni deposited on the Al at the rate to 20 to 80 angstroms per min, and deposited on Ni at the rate of 1400 angstroms per minute. Films less than 5000 angstroms thick could not be removed from the substrate. Thicker films were removed by flexing the Al and peeling away the film. The Ni films could not be magnetically saturated in a field of 65 oersteds. The appearance of the B-H curves for the films indicated a high magnetic hardness.