Study of structural relaxation of Ni 78Si 8B 14 metallic glass by electrical resistivity and thermal expansion measurements

Abstract

Electrical resistivity and thermal expansion measurements were made to elucidate the structural relaxation of Ni 78Si 8B 14 metallic glass, especially, the topological short range ordering. The decrease of the resistivity and the increase of its temperature coefficient were observed, and these changes due to the structural relaxation were discussed on the basis of the extended Ziman theory for metallic glasses proposed by Nagel. The densification of about 0.25% and the decrease of 4% in the thermal expansion coefficient were observed in the considerably relaxed sample. The topological short range ordering in Ni 78Si 8B 14 metallic glass occurs rapidly at the annealing temperature above 200°C.