Color of TiN and ZrN from first-principles calculations

The optical properties, especially the colors, of transition metal nitrides (TiN and ZrN) are studied using first-principles method. Full ab-initio procedure of color-prediction including plasma frequency is presented. The dielectric functions and reflectivity of the compounds are calculated including both intraband and interband transitions. The color of the compounds is then produced by calculating the red-green-blue color codes through the convolution of color matching functions and the calculated reflectivity. Calculated colors and screened plasma frequency for the materials are in good agreement with measurement. The color variation due to chemical doping is also studied within the rigid band approximation. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3650264]