NaBi(W0_4)_2晶体生长与光谱性能

CRYSTAL GROWTH AND SPECTRA OF NaBi(WO_4)_2

采用提拉法生长出钨酸铋钠晶体[分子式:NaBi(WO4)2,简称NBW]。生长过程中,对影响晶体开裂的原因进行了详细的分析,设计了合理的工艺参数:液面上下10mm内的温度梯度为0.8℃/mm,径向温度梯度小于O.3℃/mm。拉速为2-4mm/h,转速为10-15 r/min,降温速率为25℃/h,生长出尺寸为φ45mm×35mm的高质量的钨酸铋钠晶体。X射线衍射分析结果表明,NBW晶体属于四方晶系,空间群为I41/a。光透射测试结果表明了NBW晶体的抗辐照损伤能力强;发射光谱分析发现它的发射峰值位于可见光绿光波段。

NaBi(WO4)2(NBW) with 45 mm in diameter and 35 mm in length was grown by Czochralski method. The reason of crystal cracking was analyzed and the rational technical parameters were designed in the crystal growth process, which are: the axial temperature gradient of 0. 8 ℃ /mm in solid-liquid interface, the radial temperature gradient of 0. 3 ℃ /mm, the growth speed of 2-4 mm/h, the rotate speed of 10-15 r/min and the downing temperature speed of 25 ℃ /h. The X-ray diffraction (XRD)spectra show that the NBW single crystal belongs to cubic system with the space group of I41/a. The transmission spectra indicate that the NBW crystal has a strong antiradiation damaging feature. Its emission peak is in the range of green light wave band.