Amorphous Ni-P ultrafine particles with no Ni(OH)2 as an impurity were prepared by using a chem. reduction method, i.e. by reduction of aqueous solns. of NiCl2 and NaH2PO2. Among factors such as the initial pH value of the reaction system, additives, and reaction time, the initial pH is the most important factor in determing the yield and the properties of the products. The products were characterized by x-ray diffraction, XPS, SEM, TEM, and DSC. With an initial pH of 11, amorphous Ni-P ultrafine particles with the average diameter of ~150 nm and relatively homogeneous chem. and topol. distribution were obtained.

Key words: NICKEL ALLOYS, DISTRIBUTION OF ELEMENT, NICKEL CHLORIDE, PHOSPHORUS ALLOYS, AMORPHOUS, PHYSICAL PROPERTIES