THEORETICAL-STUDY OF TRANSITION-METAL ADHESION ON DOPED AL2O3

The effect of doping alpha-Al2O3 with an electron acceptor (Cr3+) on adhesion to first row transition metals is studied by tight-binding extended Huckel band structure calculations. Charge transfer from the metal to the partially filled t2g levels of the dopant enhance the metal-ceramic interface strength. A predicted side effect is the weakening of the Cr-O bonds in the ceramic, leading to possible adhesive failure in the first layers of the oxide phase. The adhesive energy is predicted to increase with dopant concentration, although not showing a simple linear dependence.