La~(3+)掺杂Y_2O_3透明陶瓷制备及发光性能

以Y2O3为基质材料,掺杂不同含量的La3+,采用机械力化学法制备纳米粉,粉体压制后在真空度1×10-3Pa下烧结得到La3+掺杂Y2O3透明陶瓷。采用透射电子显微镜(TEM)观察粉体一次颗粒形貌,扫描电镜(SEM)观察样品表面形貌,HV-1000型维氏硬度计测定样品硬度和断裂韧性,阿基米德法测定烧结后试样的相对密度,自动记录分光光度计测定试样透过率。结果表明:制备的La3+∶Y2O透明陶瓷透光率可达80%,掺杂La3+可以显著降低La3+∶Y2O3透明陶瓷的烧结温度;随着La2O3添加量的提高,样品透光率逐渐提高,但La2O3添加量过大会造成点阵畸变严重;随着La2O3添加量的提高,样品相对密度、维氏硬度和断裂韧性均逐渐提高,最后趋于平稳;随着保温时间延长,样品透光率也逐渐增大,继续增大保温时间,透光率趋于平缓。结合样品的透光率、相对密度、维氏硬度和断裂韧性考虑可知La2O3适合掺杂量、烧结温度和保温时间分别为10at%、1550℃和3h。

Fabrication of Y_2O_3 doped with La~(3+) transparent ceramics and luminescence properties

Y_2O_3 acted as the matrix material doped with different content of La~(3+), La~(3+) : Y_2O_3 nanocrystalline powder was prepared by mechanochemical process and La~(3+) : Y_2O_3 transparent ceramics was fabricated by vacuum sintering at 1×10~(-3) Pa.The powder was characterized by TEM.Microstructure,mechanical properties and transmittance of La~(3+) : Y_2O_3 ceramics were examined by means of SEM,hardness and fracture toughness test,and fluorescence analyzer.The results show that the transmittance of La~(3+) : Y_2O_3 transparent ceramics reachs 80% , the doping of La~(3+) greatly reduces sintering temperature of La~(3+) : Y_2O_3 transparent ceramics.With increase of La_2O_3 contents, transmittance of the ceramics increases gradually, but the lattice distortion becomes increasingly serious.The relative density,hardness and fracture toughness of the ceramics increase gradually to plateau with increasing La_2O_3 contents.The transmittance of the ceramics is improved gradually with increasing the holding time and finally tends to stable values.The optimum La_2O_3 concentration,aintering temperature and holding time for La~(3+) : Y_2O_3 ceramics are 10 at% ,1550 ℃ and 3 h,respectively, based on the experiments.