Cr4+在八面体格位中的光谱特性研究

Cr-doped and Mg, Cr-codoped Al2O3 crystals were grown by Czochralski method. The latter has a broad absorption peak in 900-1600nm region. We investigated the change of the absorption band with annealing under different atmospheres or temperatures. Through establishing a structure defect model, we successfully interpreted all the experiment results and confirmed that the extremely broad infrared absorption band belonged to Cr4+, which should occupy the octahedral sites in Al2O3.