Low-temperature specific heat study of Ni100-xZrx(x=30-80) metallic glasses

Abstract

The low-temperature specific heats of six melt-spun Ni100-xZrx, x=30, 40, 50, 60, 70 and 80 metallic glasses have been measured in the temperature range of 1.5-6K. Ni-Zr metallic glasses have no magnetic moments at least above 30 at.% Zr. Furthermore, they show a superconducting transition above 40 at.% Zr which enables the authors to deduce the electron-phonon coupling constant lambda . These facts are useful for estimating the density of states at the Fermi level and Debye temperature unambiguously. The results of the electronic specific-heat coefficient gamma increase monotonically with increasing Zr concentration. On the other hand, the Debye temperature theta D decreases monotonically with increasing Zr. The correlations between N(EF) obtained in the present work and other results both in experimental and theoretical works are discussed. The correlations between the Debye temperature theta D and crystallisation temperature Tx have been discussed in relation to Lindemann's melting theory.