Observation and Characterization of Ferromagnetic Amorphous Nickel

Abstract

Annealing an amorphous N${\mathrm{i}}_{80}$${\mathrm{B}}_{20}$ alloy results in an intermediate state that is nanocrystalline with N${\mathrm{i}}_{3}$B crystallites surrounded by an amorphous pure nickel phase. Amorphous nickel is found to be ferromagnetic with saturation magnetization about 60% of that of crystalline nickel and a Curie temperature around 60 K lower. By means of calorimetric measurements, a difference of energy of $0.028\mathrm{eV}{\mathrm{atom}}^{\ensuremath{-}1}$ between amorphous and crystalline nickel is reported.