Synthesis, characterization, and sintering behavior of Yb3Al5O12 powders

In this paper, Yb3Al5O12 powders are synthesized by a solid-state reaction method using Yb2O3 and Al2O3 powders as initial materials. The reaction path and phase evolution during the synthesis process are investigated using DSC and X-ray diffraction. High purity and well crystalline Yb3Al5O12 are obtained after calcining the mixed powders at 1150 degrees C for 2 h in air. The average particle size of the Yb3Al5O12 powders is similar to 600 nm. The crystallite size determined from FWHM of XRD reflections is similar to 53 nm. The lattice constant of Yb3Al5O12 determined by Rietveld method is a = 11.930 angstrom. And the atomic positions of Yb3Al5O12 are identified as Yb (0.125, 0, 0.25), Al(1) (0, 0, 0), Al(2) (0.375, 0, 0.25), O (0.2799, 0.1008, 0.1990). The sintering behavior of synthesized Yb3Al5O12 in air and argon atmospheres is studied by means of dilatometer. It is shown that the Yb3Al5O12 powders sintered in argon have a faster densification rate and a higher density than that sintered in air. Furthermore, bulk sample with a density of similar to 97% of the theoretical is obtained after sintering in argon for 4 h at 1600 degrees C. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.