Resistivity, Hall Constant, and Seebeck Coefficient of CsAu

Abstract

Measurements of resistivity, Hall constant, and Seebeck coefficient have established that CsAu is an $n$-type semiconductor with carrier concentrations ${10}^{18}$-${10}^{19}$ ${\mathrm{cm}}^{\ensuremath{-}3}$. The carrier concentration is essentially independent of temperature over the range 4.2-300\ifmmode^\circ\else\textdegree\fi{}K and the mobility is 30-60 ${\mathrm{cm}}^{2}$${\mathrm{V}}^{\ensuremath{-}1}$ ${\mathrm{sec}}^{\ensuremath{-}1}$. It is suggested that excess cesium introduces an impurity band which overlaps the conduction band. The Seebeck coefficient (-0.023 mV/\ifmmode^\circ\else\textdegree\fi{}K at 300\ifmmode^\circ\else\textdegree\fi{}K) indicates that the Fermi level lies about 0.02 eV above the conduction band based on optical lattice scattering.