Effect of complexing agents on the powder characteristics and sinterability of neodymium doped yttria nanoparticles

We report the synthesis of neodymium doped cubic yttria (Nd:Y2O3) nanopowders by microwave assisted combustion method using citric acid, urea and l-alanine as complexing agents as well as fuels. FTIR and XRD of powders calcined at 1000 °C for 3 h in oxygen atmosphere demonstrated formation and phase purity of Nd:Y2O3 respectively. Varied morphologies of as prepared precursor and calcined oxide (from polyhedral to spheroidal) due to different complexing agents were observed by SEM and TEM. Sintering of these nanopowders with different morphologies after compaction by cold isostatic press at 400 MPa at 1700 °C for 10 h under 10− 5 mbar vacuum gave maximum densification with 32.5% transmission by using l-alanine compared to 20% and 8% transmission obtained for urea and citric acid respectively. Thus l-alanine gave highly sinterable nanopowders with narrow size range of 25–40 nm with close to spherical morphology.