Cr^(3+)掺杂Al_2O_3-YAG共晶的生长及光谱性能研究

Growth and Optical Properties of Cr^(3+) Doped Al_2O_3-YAG Eutectic

采用光学浮区法成功地生长出了质量良好的共晶。通过XRD分析,确认了共晶组成中仅含有Al2O3和YAG两种晶相,发现随着Cr的掺入,两相的晶胞参数相对于纯单晶略有增大。通过SEM观察发现共晶组织中两种晶相无序交错排布,共晶间距约10μm左右。测量了室温下掺Cr共晶的吸收光谱、激发光谱和发射光谱。在402 nm和556 nm的激发波长下,共晶的发射谱均表现出了较好的R线发射,并在掺杂浓度达到0.4 wt%时达到极大值。其激发谱与吸收谱峰位基本一致,说明从激发态向基态跃迁时,发生无辐射跃迁的概率很小。通过与两种单晶的光谱的对比,确认进入Al2O3中八面体的Cr3+在共晶的光谱性质中起主要作用。

Cr3＋ doped YAG-Al2O3 eutectic was grown by the optical floating zone method. The as-grown eutectic was composed of only YAG and AIEO3 phases, and SEM image showed that the lamellar space was about 10 μm when the growth speed is 7 mm/h. The absorption, excitation and luminescence spectra were investigated. Sharp phosphorescence designated as R-lines were observed while excitated at 402 nm and 556 nm, and came to the largest intensity at 0.4 wt% concentration. By comparing the sepctra of the eutectic and single crystal, a conclusion could be deduced that the Cr3＋ in the A1203 site played a major role in the optical properties of eutectic.