A theoretical investigation of the crystal structure and electronic characters of trivalent Er3+ doped Yttrium Aluminum Garnet

Abstract Rare-earth Erbium-doped yttrium aluminum garnet (Er: YAG) shows great research interests in many kinds of solid-state lasers. However, the crystal structures of Er: YAG are unclear. Herein, we conduct a systematic exploration of the microstructure of Er-doped YAG crystal by using the CALPSO method with first-principle calculations. A novel structure with the Er3+ impurity concentration of 4.16% is identified, which belongs to C222 space group. It is found that the impurity Er3+ ion substitutes the central site of Y3+ ion in the host crystal lattice. This work could provide important information for understanding the rare-earth doped laser materials.