Electrical transport and optical properties of zirconium nitride/aluminum nitride multilayers

We have synthesized zirconium nitride/aluminum nitride multilayered thin films with a reactive sputtering technique. The electrical transport and optical properties of these multilayers have been examined by resistivity, Hall effect, and near-normal incidence reflectance and transmittance measurements. We show the existence of a metal-to-insulator transition and strong increase of Hall coefficient at small wavelength of composition modulation. The optical response of the multilayers is systematically modified from the behavior of the individual constituents. The measured optical response is in qualitative agreement with a simple effective-medium theory