An analysis for measurement of thermal diffusivity components of anisotropic platelike samples by AC calorimetric method

This work examines the effects of anisotropy and transparency on measuremen ts of thermal diffusivity components with an ac calorimetric method associa ted with laser heating. Analytical results indicate that the region where t he two-dimensional effect occurs increases with the decrease of the ratio o f cross-plane to in-plane thermal diffusivity. The region also increases wi th the optical thickness of the sample. The linear relations, as indicated by a decay constant from which the cross-plane thermal diffusivity is deduc ed, are not obtained for media of both optically moderate and thin thicknes s, while at sufficiently large optical thickness, anisotropy and two-dimens ional effects are found insignificant.