Effects of Cr3+ concentration on the crystallinity and optical properties of Cr-doped Al2O3 powders by solid-state reaction method

The Al2O3 crystal contains a little of amount of Cr3+, which name is ruby, is applied to ruby laser. In our research, Al2O3: Cr3+ powder material is prepared via solid state reaction. Effects of different Cr3+ concentration on the crystallinity and optical properties of the material were investigated. The experimental results indicate that the material shows good crystallinity at 1200°C. The α crystal of Al2O3: Cr3+ powder is improved its optical properties. Moreover, the optical of Al2O3: Cr3+ increases by the Cr3+ concentration’s increasing until 0.3 wt%. Then, the optical of Al2O3: Cr3+ decreases by the Cr3+ concentration’s increasing until 0.3 wt%. So the 0.3 wt% of Cr3+ is the best results. This kind of luminescence material has a very obvious emission peak under the incident light of 694nm.