Effect of cerium oxide in reinforcing the properties and densification of yttria ceramics

Abstract

Synthesis of high-quality nanostructured Yttria/Ceria (Y2O3/CeO2) nanocomposite and the effect of ceria in reinforcing the properties of yttria are presented in the paper. The ultrafine starting powder is synthesized by a single step modified combustion technique and its green pellet is densified by a microwave sintering technique. The as-synthesized sample is characterized using X-ray diffraction (XRD) for determining the crystalline structure. All the peaks were indexed for a cubic structure of Y2O3 (ICDD: 89-5591) and CeO2 (ICDD: 81-0792). The crystallite size calculated for the highest peak (222) using the Debye-Scherrer equation is 24.05 nm. The crystallite sizes are in the range of 16-25 nm. The structural properties of the combustion product are examined by high-resolution transmission electron microscopy (HRTEM). Phase purity is ascertained by FTIR spectroscopy. The optical transmittance is examined by UV-Visible spectroscopy. The sample shows a band gap of 3.42 eV and a high refractive index of 2.36. The theoretical transmittance in the UV-Visible range is 71.8%. The nanopowder is compacted to pellets by hydraulic pressing and densified to 99.5 % of theoretical density at 1450 0C with a ramp rate of 200C/min for a soaking duration of 30 min which is better compared to pure yttria. The morphological investigations are done using field emission scanning electron microscopy (FESEM). The properties show that the sample can be effectively used to fabricate infrared transparent ceramic material.Synthesis of high-quality nanostructured Yttria/Ceria (Y2O3/CeO2) nanocomposite and the effect of ceria in reinforcing the properties of yttria are presented in the paper. The ultrafine starting powder is synthesized by a single step modified combustion technique and its green pellet is densified by a microwave sintering technique. The as-synthesized sample is characterized using X-ray diffraction (XRD) for determining the crystalline structure. All the peaks were indexed for a cubic structure of Y2O3 (ICDD: 89-5591) and CeO2 (ICDD: 81-0792). The crystallite size calculated for the highest peak (222) using the Debye-Scherrer equation is 24.05 nm. The crystallite sizes are in the range of 16-25 nm. The structural properties of the combustion product are examined by high-resolution transmission electron microscopy (HRTEM). Phase purity is ascertained by FTIR spectroscopy. The optical transmittance is examined by UV-Visible spectroscopy. The sample shows a band gap of 3.42 eV and a high refractive index of 2...