Experimental thermoelectric power of liquid silver-germanium alloys interpreted with an analytical energy-dependent calculation

摘要

The absolute thermoelectric power of liquid Ag-Ge alloys has been measured as a Function of temperature over the whole phase diagram in 10 at.% steps, from the liquidus to 1150 degrees C. To interpret these original measurements we present an analytical expression of the thermoelectric power of the liquid alloys within the extended Faber-Ziman formalism in terms of partial structure factors and t-matrix formulation including, for the first time to our knowledge, an analytical expression of the energy-dependent contribution. The experimental first peak asymmetry of both germanium and silver structure factors cannot be reproduced with hard spheres. The Silbert-Young (1976, Phys. Lett. A, 58, 469) square-well potential describes them better for pure metal. To minimize the uncertainty in the knowledge of the partial structure factors in the electronic transport properties of liquid metals, we used the same model extended to alloys by Gopala Rao and Das (1987, Phys. Rev. B, 36, 6325). The muffin-tin potential used in this calculation to determine the t matrix is derived both from a screened ionic and from a neutral atomic potential. [References: 39]