Article ID Journal Published Year Pages File Type
1606130 Journal of Alloys and Compounds 2016 9 Pages PDF
Abstract
Yttria (Y2O3) nano-powders were synthesized by the normal-strike precipitation method. The influences of R (NH4HCO3/M3+, molar ratio) and ammonium sulfate addition were studied throughout the preparation process. Several analytic techniques such as XRD, TG/DSC, SEM and FTIR were used to determine the characteristics of the precursors and Y2O3 powders. It was found that morphologies and phases of the precursors were evidently influenced by the R value. The phases of the precursors were Y2(CO3)3·2.79H2O when R was 3-4, while the composition of the precursors with R = 4-5 was (NH4)aY(OH)b(CO3)c·xH2O. Homogeneous needle-flake shaped particles composed of coadjacent grains with diameters of about 70 nm were obtained as the R = 3-4. The rhombohedral flake-shaped particles were the products with R = 5-6. The mechanism of the influence of R value on the precipitation of the precursor was also investigated in this work. Pure Y2O3 nano-powders were obtained by calcining the precursors at 1000 °C for 4 h regardless of what the R value was. Sulfate ions affect not only dispersion of nanopowders, but also their grain size. Results obtained in this work are contributed to the controllable synthesis of yttria powders.
Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys
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