Studies on Growth and Characterization of High Quality Metal Oxide Single Crystals

高质量的金属氧化物单晶已经应用于许多电子器件。本研究旨在阐明漂浮区法生长金红石和三金红石单晶以及水热法生长石英单晶的方法和表征。研究结果表明：(1)添加Al、Zr、Sc后，金红石型单晶生长无小角度晶界。晶体的光学质量优于用Verneuil法生长的商用晶体。(2)成功地用FZ法生长了具有三金红石型结构的MgTA_2O_6单晶。在白光下，普通光线和非常光线的折射率分别为2.07和2.18，双折射为0.11。用同样的方法生长了淡绿色的NiTa_2O_6单晶。晶体在300-500,650-900和1100-1600 nm范围内有较强的吸收光谱。(3)在水热条件下，在230-280ﾟC和4-100 Mpa的条件下，从氟化铵溶液中生长出石英单晶。Z面的最大生长速率达到0.88 mm/d，与碱性溶液中的生长速率相当。Z生长区的线缺陷密度约为10^3~10^5个/cm~2，高于碱性溶液。FTIR光谱在3500 cm~(-1)&gt；by-OH伸缩振动处有很强的吸收。

High quality metal oxide single crystals have been applied to many electronic devices. This study is to clarify the growth and characterization of rutile and trirutile single crystals by floating zone method, and also quartz single crystals by hydrothermal method. Following results were obtained through this investigation.(1) Rutile single crystals free from low-angle grain boundaries were grown with the addition of Al, Zr and Sc. Optical quality of the crystals was superior to that of commercially available crystals grown by the Verneuil method.(2) MgTa_2O_6 single crystals which has trirutile structure were successfully grown by FZ method. The refractive indices for ordinary and extraordinary rays were 2.07 and 2.18 under white light, respectively, and birefringence was 0.11. Pale green NiTa_2O_6 single crystals were also grown by the same method. The crystals had strong absorption spectra in the wave length ranges of 300-500,650-900 and 1100-1600 nm.(3) Quartz single crystals were grown from ammonium fluoride solutions at 230-280 ﾟC and 4-100 MPa under hydrothermal condition. The maximum growth rate of the Z face attained 0.88 mm/day which was comparable to that in alkaline solutions. The linear defect density in Z growth zone was about 10^3-10^5 pcs/cm^2, higher than that alkaline solutions. Strong absorption at about 3500cm^<-1> by -OH streching vibration was observed in FTIR spectra.