Sintering and Oxygen Ionic Conducting Properties of Bi2V0.9Co0.1O5.5-δ Derived from an EDTA-Citrate Precursor
Bi2V0.9Co0.1O5.5-δ with a pure Aurivillius phase was synthesized by a sol-gel method using EDTA and citric as mixed complexing agents. It was found that homogeneous and fine powder (100-200 nm) with a pure Aurivillius phase can be produced by calcining the complex precursor at 450 °C for 1h in air. The sintering properties of Bi2V0.9Co0.1O5.5-δ were investigated in the range of 560-680 °C with respect to relativity density. Sintering at 640 °C was ascertained to be preferred for Bi2V0.9Co0.1O5.5-δ, producing a dense microstructure with uniform grains around 3-5 μm. The Bi2V0.9Co0.1O5.5-δ ceramic exhibits an oxygen ionic conductivity of 1.0×10-1 S·cm-1 at 600 °C. The difference between the activation energies for the ionic conducting in low and high temperature regions is qualitatively interpreted in terms of an order-disorder phase transition. This research demonstrates the advantage of the EDTA-citrate method in preparing Bi2V0.9Co0.1O5.5-δ with respect to the simplicity of synthesis process, desired morphology of synthesized powder, low sintering temperature and superior ionic conducting properties of ceramic specimen.
Byung Tae Ahn, Hyeongtag Jeon, Bo Young Hur, Kibae Kim and Jong Wan Park
F. Zhang et al., "Sintering and Oxygen Ionic Conducting Properties of Bi2V0.9Co0.1O5.5-δ Derived from an EDTA-Citrate Precursor", Solid State Phenomena, Vols. 124-126, pp. 731-734, 2007