The reaction between Ni2+ and H2PO2- in aqueous solution for the preparation of Ni-P ultrafine amorphous alloy usually took place at elevated temperature, e.g., at 100? The reaction can be carried out at room temperature by adding a very small amount of inducing reagent such as KBH4. Thereby, the reaction kinetics and the influence of reaction conditions were studied by measuring the vol. of H2 evolved during the reaction. The results showed that the reaction rate can be expressed by a second order autocatalytic reaction equation with respect to the reactant H2PO2- and the Ni-P product. The activation energy of the reaction was found to be about 60 kJ/mol. PH value of the reaction solution did not affect the rate constants, but influenced the incubation period (longer incubation period at higher pH value). Generally, the reaction completed with 40 min. Interestingly, the Ni-P amorphous alloy produced in this way formed spherical particles with uniform size because the nuclei of metallic nickel formed at one time when the inducing reagent was added and the reaction occurred only on the surface of the nuclei at room temperature

Key words: TRANSMISSION ELECTRON MICROSCOPY, NICKEL ALLOYS, REACTION KINETICS, X-RAY DIFFRACTION ANALYSIS, X-RAY PHOTOELECTRON SPECTROMETRY, ICP-ATOMIC EMISSION SPECTROMETRY, PHOSPHORUS ALLOYS, AMORPHOUS ALLOY