Fabrication of polycrystalline (Y0.7Gd0.3)2O3:Eu3+ ceramics: The influence of initial pressure and sintering temperature on its morphology and photoluminescence activity

• Published in: Ceramics international Vol. 38; no. 2; pp. 1303 - 1313
• Main Authors: Krsmanovic, R M, Antic, Z, Bartova, B, Brik, M G, Dramicanin, M D
• Format: Journal Article
• Language: English
• Published: 01.01.2012
• Subjects: Ceramics; Compacting; Grains; Morphology; Nanocomposites; Nanomaterials; Nanostructure; Sintering (powder metallurgy)
• ISSN: 0272-8842
• DOI: 10.1016/j.ceramint.2011.09.004

Nanocrystalline (Y0.7Gd0.3)2O3 powder, synthesised by the polymer complex solution method, was compacted into 25 pellets by applying high pressures (173-867 MPa) for 30 s and were subsequently sintered at different temperatures (800-1400 C) for 18 h. The morphology and optical characteristics of the starting powder and prepared ceramic samples were investigated to identify the changes induced by the variations of initial compacting pressure and sintering temperature. The grain size tended to decrease with increasing pressure, even when elevated temperatures were used for annealing, while a low compacting pressure resulted in grain coarsening and, in some cases, even in an anomalous morphology of the ceramic samples. Luminescence emission in the ceramics decayed faster than in the nanopowders, which is in agreement with the grain formation and gradual transformation to the bulk material. Judd-Ofelt intensity parameters and branching ratios were calculated taking into account the difference in effective refractive index for nanopowder and ceramic samples.