Preparation Of Yb: Y_2-2xLa_2xO₃ Powder And Ceramics By Citrate Method

Yb:Y2-2xLa2xO3 powders and ceramics were prepared by citrate method in this paper. The powders of Yb:Y2-2xLa2xO3 (x value between 0.1~0.4) were synthesized and the Yb:Y2-2xLa2xO3 ceramics (x=0.1and 0.2) by using these powders were sintered in atmosphere. By means of modern analyses techniques, such as XRD, TEM, SEM, laser particle size analysis et al., the crystallization and the microstructure properties of Yb:Y2-2xLa2xO3 powder and ceramics were investigated. The main conclusions obtained from above-mentioned work are as follows:1. Loose Yb:Y2-2xLa2xO3 gel precursor can be obtained when the proportion of metal cations and citric acid is 1:1.2.2. The XRD patterns of Yb:Y2-2xLa2xO3 powders synthesized by citrate method indicate that the powder (x=0~0.4) have formed the body centre cubic structure. And the lattice constant is increased with the increasing of x value. The average particle size of the powders is between 100nm and 200 nm, and the average particle size of the powders is increased with the increasing of x value at same calcining temperature. The grain size can become smaller and the grain distribution become uniformity by grind with ethanol. The average particle size of the grinded Yb:Y1.8La0.2O3 powders is less than 70nm. The distribution of the powders size is belonged to normal distribution on the whole and the shape of the particles is subsphaeroidal.3. The gel precursor of Yb:Y2-2xLa2xO3 and YAG form the final polycrystal without intermediate phases in calcining process by citrate method. Full crystalline YAG powders can be obtained by calcined at 850℃and the synthesis temperature of YAG powders by citrate method is lower than that by coprecipitation method.4. The Yb:Y2-2xLa2xO3 ceramics (x=0.1and 0.2) were sintered in atmosphere. The perfect sintering temperature is different with different lanthanum content. The perfect sintering temperature of Yb:Y1.8La0.2O3 and Yb:Y1.6La0.4O3 ceramic is about 1600℃, 1550℃, respectively.