Cr^(4+)在八面体格位中的光谱特性研究

Spectroscopic behavior of Cr^(4+) in octahedral sites

采用提拉法生长了Cr单掺和Cr,Mg共掺Al2O3晶体,后者具有900—1600nm的宽带吸收.研究了该吸收带在不同气氛、不同温度退火下的变化规律.通过建立合理的晶格缺陷模型,成功地解释了所有的实验结果,并确定Cr,Mg共掺Al2O3晶体红外波段宽吸收带属于八面体格位中的Cr4+离子.

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 Cr^4＋ , which should occupy the octahedral sites in Al2O3 .