Ab Initio Calculation of the Cr K Edge in alpha-Al2O3:Cr3+
Résumé
The red color of ruby (-Al2O3:Cr3+) is assigned to transitions between 3d states of the chromium ion. A precise description of the structural and electronic environment of the Cr3+ ion in its slightly distorted octahedral site (C3 symmetry) is needed to understand the cause of the color. We have analysed the Cr K-edge in -Al2O3:Cr3+with a reciprocal space approach that allows the computation of self-consistent spin polarized charge density for large unit cells, beyond the traditional “muffin-tin” approximation. Structural and electronic information is deduced from the calculation.