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

Thermophysical propel ties 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 hemi spherical total emissivity, the constant-pressure specific heat capacity, t he surface tension, and the electrical resistivity. The measured density ca n be expressed by p(liq) = 5.67 x 10(3) - 0.542 (T - T-m) kg(.)m(-3) from 1 150 to 1400 K with T-m= 1211.3 K. the volume expansion coefficient by alpha = 0.9656 x 10(-4) K-1, and the hemispherical total emissivity at the melti ng temperature by epsilon(T), (liq)( T-m)= 0.17. Assuming constant epsilon( T), (liq)(T) = 0.17 in the liquid range that has been investigated, the con stant-pressure specific heat was evaluated as a function of temperature. Th e surface tension over the same temperature range can be expressed by sigma (T)= 583-0.08(T - T-m) mN(.)m(-1) and the temperature dependence of the ele ctrical resistivity, when r(liq)( T-m) = 60 mu Omega(.)cm is used as a refe rence point, can be expressed by r(c, liq)(T) = 60 + 1.18 x 10(-2)(T - 1211 .3) mu Omega(.)cm. The thermal conductivity, which was determined from the resistivity data using the Wiedemann-Franz-Lorenz law, is given by kappa(li q)(T) = 49.43 + 2.90 x 10(-2)(T - T-m) W(.)m(-1) K-1.