SPHERICAL AMORPHOUS NICKEL-PHOSPHORUS ALLOY PARTICLES WITH UNIFORM SIZE PREPARED AT ROOM-TEMPERATURE

A new chemical method for preparing ultrafine amorphous Ni85P15 alloy particles with uniform size and spherical shape is reported. The parti cles were prepared by reduction of nickel chloride with sodium hypopho sphite initiated with a drop of potassium borohydride solution at room temperature. The preparation mechanism, which consists of primary nuc leation of Ni-B followed by autocatalytic deposition of the components , is discussed. The amorphous structure of the particles was identifie d by X-ray diffraction and selected area electron diffraction. X-ray p hotoelectron spectroscopy indicated that nickel and phosphorus are pre sent as an alloy. Transmission election microscopy revealed that the p articles are uniform and spherical with a diameter of about 100 nm.