Thermopower and resistivity of amorphous and crystalline NiP

Abstract

Data are presented for the thermopower and electrical resistivity of amorphous and crystalline ${\mathrm{Ni}}_{76}$${\mathrm{P}}_{24}$. Mean-free-path effects are large in the electrical resistivity but appear to be less significant in the thermopower. The diffraction model, modified to include the Pippard-Ziman constraint on the electronphonon interaction, is used to derive an expression for the thermopower in high-resistivity systems. The data on the amorphous phase are consistent with this modified diffraction model. The $s\ensuremath{-}d$ model predictions, in contrast, are an order of magnitude too large and of the wrong sign.