Abstract
Non-local calculations have been made of the eddy currents set up in spherical metal particles, and the results are used to discuss the infrared absorption of such particles. For diffuse surface scattering the absorption is reasonably approximated by the use of a mean free path equal to the particle radius, but for specular or mixed scattering the absorption is strongly enhanced. Comparison with experiment indicates that specular scattering may partially explain the almost universal observation that absorption by ultrafine metallic particles is larger than expected.