Abstract:
The relative importance of different heat transfer mechanisms is evaluated, and thermal conduction is found to dominate under most conditions achieved n the diamond anvil cell.
The temperature distribution is
calculated for metals and dielectrics heated by a laser. A comparison of
calculated and measured temperature profiles across laser-heated
perovskite samples indicates that the thermal conductivity is inversely
proportional to temperature, as expected for dielectrics in which thermal
conduction is due to phonon transport. A model is developed which relates
laser power and sample temperature and permits the determination of thermal
conductivity and absorption at high
pressures and temperatures.
The bias introduced by axial
temperature gradients on measurements is negligible
for experiments
in which a metal foil is heated, but may lead to underestimating melting
temperatures by 10% for dielectric samples at 4000 K.