Experimental magnetic-susceptibility study of the electronic properties of liquid Se-Te alloys

Abstract

The electronic properties of liquid Se-Te alloys have been investigated by measurement of the magnetic susceptibility $\ensuremath{\chi}$ in a temperature range up to 1100\ifmmode^\circ\else\textdegree\fi{}C. $\ensuremath{\chi}$ is assumed to be composed of a temperature-independent diamagnetic term ${\ensuremath{\chi}}_{D}$ and a paramagnetic contribution ${\ensuremath{\chi}}_{p}$. ${\ensuremath{\chi}}_{D}$ is found to be a linear function of composition. In the Te-rich alloys, ${\ensuremath{\chi}}_{p}$ is proportional to the square root of electrical conductivity indicating diffusive electronic transport. In the Se-rich alloys, the temperature dependence of ${\ensuremath{\chi}}_{p}$ is found to be exponential with a composition-independent activation energy of 0.68 eV. This is interpreted as the energy required to produce a paramagnetic dangling bond. The entropy of bond breaking is found to increase strongly with Te content.