Effective Thermal Conductivity of Metal–Dielectric Composites at the Non-dilute Limit

Abstract

Based on the Bruggeman integral principle and Ordonez-Miranda et al. (J. Appl. Phys. 111, 044319 (2012)) model, formulas for predicting the effective thermal conductivity of composites containing not only low but also high concentrations of spherical and cylindrical metallic particles embedded in a dielectric matrix are derived and analyzed. In the dilute limit of particles, the obtained results coincide with those previously reported in the literature. In the non-dilute limit, on the other hand, the thermal conductivity of the composites shows a remarkable enhancement, which increases with the relative radius of the particles with respect to the coupling length. It is shown that the effect of electron–phonon coupling on the thermal conductivity of composites gets strength at high-volume fractions of particles and is cancelled out for high interfacial thermal resistances. The proposed model could be useful for predicting the thermal conductivity of particulate composites with metallic particles with sizes from macro/micro- to nanoscales.