Properties of chemically prepared MmNi4.52Mn0.49 alloy

MmNi_4.52Mn_0.49 (Mm is mischmetal) alloy was prepared by a coprecipitation-reduction process. The alloy structure, chemical composition, particle size and surface properties were investigated by using the analysis of X-ray diffraction, inductively coupled plasma emission spectroscopy, particle size analysis and X-ray photoemission spectroscopy. Pressure-composition isotherms of the chemically prepared alloy were measured. The alloy powder was evaluated as the active material of a metal hydride electrode. It is found that the alloy thus obtained has larger specific surface area, different surface states, lower activation energy for hydrogen absorption/desorption and better electrode characteristics than the alloy prepared by conventional arc-melting.