High energy transmission of Al2O3 doped with light transition metals.

The transmission of transparent colored ceramics based on Al(2)O(3) doped with light transition metals is measured in the visible and infrared range. To clarify the role of the dopands we perform ab initio calculations. We discuss the electronic structure and present optical spectra obtained in the independent particle approximation. We argue that the gross spectral features of Co- and Ni-doped Al(2)O(3) samples are described by our model, while the validity of the approach is limited for Cr-doped Al(2)O(3).