MEASUREMENTS OF THERMOPHYSICAL PROPERTIES OF MOLTEN SILICON BY A HIGH-TEMPERATURE ELECTROSTATIC LEVITATOR

Several thermophysical properties of molten silicon measured by the hi gh-temperature electrostatic levitator at JPL are presented. They are density, constant-pressure specific heat capacity, hemispherical total emissivity, and surface tension. Over the temperature range investiga ted (1350 < T-m < 1825 K), the measured liquid density (in g.cm(-3)) c an be expressed by a quadratic function, rho(T) = rho(m) - 1.69 x 10(- 4)(T - T-m) - 1.75 x 10(-7)(T - T-m)(2) with T-m and rho(m) being 1687 K and 2.56 g.cm(-3), respectively. The hemispherical total emissivity of molten silicon at the melting temperature was determined to be 0.1 8, and the constant-pressure specific heat was evaluated as a Function of temperature. The surface tension (in 10(-3) N.m(-1)) of molten sil icon over a similar temperature range can be expressed by sigma(T) = 8 75 - 0.22(T - T-m).