  In a complementary article, we exploited algebraic properties of Maxwell's
equations and fundamental principles such as electromagnetic reciprocity and
passivity, to derive fundamental limits to radiative heat transfer applicable
in near- through far-field regimes. The limits depend on the choice of material
susceptibilities and bounding surfaces enclosing arbitrarily shaped objects. In
this article, we apply these bounds to two different geometric configurations
of interest, namely dipolar particles or extended structures of infinite area
in the near field of one another, and compare these predictions to prior
limits. We find that while near-field radiative heat transfer between dipolar
particles can saturate purely geometric "Landauer" limits, bounds on extended
structures cannot, instead growing much more slowly with respect to a material
response figure of merit, an "inverse resistivity" for metals, due to the
deleterious effects of multiple scattering; nanostructuring is unable to
overcome these limits, which can be practically reached by planar media at the
surface polariton condition.
