Solar experimental methods for observing melting plateaux and associated temperature measurements for refractory oxides from 2000 to 3000 °C

Melting points of refractory oxides at high temperature can be obtained through different techniques (resistive furnaces, induction furnaces, laser beams, imaging furnaces …). Here, we present a solar furnace experimental setup and methods developed at the Odeillo Solar Furnace (IMP-CNRS) and used to measure melting and freezing plateau temperatures between 2000 and 3000 °C. ail a new procedure we have developed that produces a controllable, long duration temperature plateau, and we discuss the appropriate temperature measurement method. inciple is to heat a self-crucible product with the solar concentrated flux and to preserve the thermal equilibrium at the melting point temperature by providing a continuously regulated solar flux supply. Two critical points are treated: the control of the right level of temperature and its measurement, which is hampered by the solar reflection. s obtained with Al2O3 (melting point = 2053 °C) are presented as example.