Temperature Dependence of the Total Interference Functions of Liquid Cu-Sn Alloys

Abstract

The total interference function I (K), which is a weighted sum of the partial interference functions, and the corresponding weighted distribution function have been calculated from the elastic x-ray scattering of liquid Cu-Sn alloys with 20 and 22.5 at.% Sn measured at temperatures between 800 and 1160\ifmmode^\circ\else\textdegree\fi{}C. The total I(K) of the alloys show a slight decrease in the position ${K}_{1}=\frac{4\ensuremath{\pi}({sin\ensuremath{\theta}}_{1})}{\ensuremath{\lambda}}$ and in height of the first peak with increasing temperature [${K}_{1}=2.88$ ${\mathrm{\AA{}}}^{\ensuremath{-}1}$ and $\mathrm{I}({K}_{1})=3.05$ at 800\ifmmode^\circ\else\textdegree\fi{}C, and ${K}_{1}=2.86$ ${\mathrm{\AA{}}}^{\ensuremath{-}1}$ and $\mathrm{I}({K}_{1})=2.50$ at 1160\ifmmode^\circ\else\textdegree\fi{}C]. On using the total $\mathrm{I}(K)$ in the Faber-Ziman theory of electrical resistivity ${\ensuremath{\rho}}_{R}$ and thermoelectric power $Q$ of binary liquid alloys, one obtains theoretical values of ${\ensuremath{\rho}}_{R}$ and $Q$ which decrease slightly with increasing temperature in agreement with the experimental results of Roll and Motz and Howe, respectively.