Determination of nanoscale heat conductivity by time-resolved X-ray scattering

Heat transfer in thin films on a substrate is determined by time-resolved X-ray scattering following pulsed laser excitation. The temperature of the top layer of gold can be resolved via the shift of the powder reflections following the heating pulse on a 100 picosecond time scale. The decay of transient heating is compared to models of heat transfer across the hetero-interface and heat conduction in bulk in order to determine surface-near thermal parameters.