Cross-plane thermal conductivity and thermal diffusivity measurement in thin-films by one-dimensional thermal wave method

A novel approach for cross-plane thermal conductivity and diffusivity measurement in thin-films by combining steady state comparative-longitudinal heat flow method (SCHF) and the Angström method is reported. A thin specimen was sandwiched between two identical metal cylinders; thermal wave was introduced from the lower cylinder and crossed through the specimen then passed to the upper cylinder where steady heat flux is enforced. There were four equally spaced thermocouples on both upper and lower cylinders to record the temperature change along the cylinder column. By solving the one-dimensional (1D) heat conduction equations, thermal diffusivity and thermal conductivity can be deduced simultaneously. Thermal diffusivity and thermal conductivity of Polytetrafluoroethylene (PTFE) films with different thickness were measured, and the results are in a good agreement with reported standard value.