The semiconductor-metal transition of liquid tellurium-arsenic mixtures

The Hall coefficients, RH, conductivity, σ, and the EXAFS spectra of liquid As–Te mixtures containing 0–40 at.% As have been measured up to 600°C. There are three regimes: I (semiconducting state), II (strong scattering state) and III (metallic state) in the temperature dependence of RH. From EXAFS measurement it is found that the As–Te bonds break with increasing temperature, which coincides with a rapid decrease of RH in regime II, and consequently the network structure of liquid As–Te mixtures is transformed into a chain like structure around 500°C. The structural transformation induces the transition from a semiconductor to metal.