Determination of the intrinsic temperature dependent thermal conductivity from analysis of surface temperature of laser irradiated materials

摘要

An experimental and analytical approach is described to determine the temperature dependent intrinsic lattice thermal conductivity, k(T), for a broad range of materials. k(T) of silica, sapphire, spinel, and lithium fluoride were derived from surface temperature measurements. Surfaces were heated from room temperature up to 3000 K using a CO_2-laser irradiance ≤5 kW/cm~2. The solution of the nonlinear heat flow equation was used to extract parameters of k(T) =A × T~ε, where -1.13≤ε≤0 depending on the material. Results generally show good agreement with reported k(T). Below evaporation, the phonon-only k remains the dominant heat transport mechanism during laser heating.