Resistivity, Hall Constant, and Seebeck Coefficient of CsAu

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