Infrared magnetic response in a random silicon carbide micropowder

We generalize the theoretical model of magnetic metamaterials made of dielectric particles to treat random particle sizes, shapes, and orientations. We demonstrate that the magnetic-dipole response of these randomly shaped subwavelength particles can be approximated with Mie theory as though they were spheres, while a quasistatic ellipsoidal approximation is used for the electric-dipole response. We verify our model with experimental measurement of a bulk magnetic response in a micropowder of milled SiC particles. Using such a crude powder could lead to immensely simplified negative permeability inclusions for negative index metamaterials.