First-principle calculations on color center in Y–Al–O system

Based on a serial of ab initio calculations, we studied various F-type color centers in Y–Al–O system material: α-Al2O3, Y2O3, Y3Al5O12 (YAG), YAlO3 (YAP). The local atomic structures and formation energy of various color centers are calculated and discussed among the above four oxides. The stability of various color centers in Y–Al–O material is analysed. Our results show that the neutral F-center needs the largest formation energy while, +2 charged F2+-center needs the lowest formation energy in each of studied oxides. Same type of color center in α-Al2O3 needs the lowest formation energy, while needs the largest energy in YAG. And more, in all four oxides, the F2+-center is relatively stable than other two species.