Effect of hydrogen and deuterium on electronic-transport properties of the metallic glassPd0.76Cu0.06Si0.18

Abstract

The effect of hydrogen and deuterium on the temperature dependence of resistivity $\ensuremath{\rho}$ and thermoelectric power $S$ for the metallic glass ${\mathrm{Pd}}_{0.76}$${\mathrm{Cu}}_{0.06}$${\mathrm{Si}}_{0.18}$ is reported. Between 4.2 and 296 K it was found that the addition of hydrogen increases $\ensuremath{\rho}$ and decreases its temperature coefficient $\ensuremath{\alpha}=(\frac{1}{\ensuremath{\rho}})\frac{d\ensuremath{\rho}}{\mathrm{dT}}$. For $4.2<T<90$ K the extra resistivity due to hydrogen, $\ensuremath{\Delta}\ensuremath{\rho}(T)$, decreases with increasing $T$ in a manner best fitted by the form $a\ensuremath{-}b{[\mathrm{ln}(\frac{T}{{T}_{K}})]}^{2}$, where $a$, $b$ are constants and ${T}_{K}=1$ K. For the unhydrogenated glass $S$ is small, negative, and linear in $T$ with a negative slope throughout the range $25<T<210$ K in which it was measured. Upon hydrogenation $\frac{\mathrm{dS}}{\mathrm{dT}}$ becomes less negative. The isotope effect in [$\frac{\ensuremath{\Delta}\ensuremath{\rho}(T)}{\ensuremath{\Delta}\ensuremath{\rho}(296 \mathrm{K})}$] is very small. These data are discussed in the light of two current models of electronic transport in amorphous metals.