Thermophysical properties of molten germanium measured by a high-temperature electrostatic levitator

Thermophysical properties of molten germanium have been measured using the high-temperature electrostatic levitator at the Jet Propulsion Laboratory. Measured properties include the density, the thermal expansivity, the hemispherical total emissivity, the constant-pressure specific heat capacity, the surface tension, and the electrical resistivity. The measured density can be expressed by rho sub(liq) identical with 5.67x10 super(3)-0.542 (T-T sub(m)) kg times m super(-3) from 1150 to 1400 K with T sub(m) identical with 1211.3 K, the volume expansion coefficient by alpha identical with 0.9656x10 super(-4) K super(-1), and the hemispherical total emissivity at the melting temperature by epsilon sub(T, liq)(T sub(m)) identical with 0.17. Assuming constant epsilon sub(T, liq)(T) identical with 0.17 in the liquid range that has been investigated, the constant-pressure specific heat was evaluated as a function of temperature. The surface tension over the same temperature range can be expressed by sigma (T) identical with 583-0.08(T-T sub(m)) mN times m super(-1) and the temperature dependence of the electrical resistivity, when r sub(liq)(T sub(m)) identical with 60 mu Omega times cm is used as a reference point, can be expressed by r sub(e, liq)(T) identical with 60+1.18x10 super(-2)(T-1211.3) mu Omega times cm. The thermal conductivity, which was determined from the resistivity data using the Wiedemann-Franz-Lorenz law, is given by Kappa sub(liq)(T) identical with 49.43+2.90x10 super(-2)(T-T sub(m)) W times m super(-1) times K super(-1).