  Radiative heat exchange of spherical particles between each other and with
thick polarizable plates is studied in the framework of fluctuation
electrodynamics. An additive dipole approximation for the thermal conductance
of micrometer sized particles is proposed. The numerical calculations are
performed for particles and plates made of gold and silica. Several theoretical
models of radiative conductance are compared and juxtaposed with the known
experimental data.

Other Condensed Matter