Eu^(3+):LiNbO_3单晶的坩埚下降法生长及其光谱性质

Growth of LiNbO_3 single crystals doped Eu^(3+) by Bridgman method and their fluorescence spectra

选用合适的温度梯度(20~30℃/cm)与生长速度(1~3mm/h),用坩埚下降法成功地生长出了掺杂Eu3+的LiNbO3 单晶。用X射线衍射及DTA分析表征了获得的晶体。生长的晶体无宏观缺陷,在 He Ne激光的照射下,无散射中心。测定了从生长初期下部到生长后期上部晶体的紫外 可见吸收光谱与荧光光谱。观测到分裂的光谱线。结果表明,沿着晶体生长方向,Eu3+浓度逐步减少。Eu3+ 离子在晶体中取代Li与Nb格位。

By means of the optimum conditions such as proper raw materials, growth rate of 1～3mm/h and convex or plane solid-liquid interface with temperature gradient around 20～30℃/cm, large size crystal containing 0.1mol% Eu^(3+) ion with good optical property without micro-defects were obtained by the Bridgman method. X-ray and DTA were characterized the crystals. The crystal shows no impurity center under the irradiation of He-Ne laser. The UV/Visible Absorption and emission spectra of upper and lower part of crystal were measured. The splitting emission lines were observed. The results showed that the concentration of Eu^(3+) in LN crystal reduced along the direction of crystal growth, and the Eu^(3+) ions occupied Li and Nb sites in LiNbO_3 crystal.