Effect of annealing atmosphere on the structural and electrical properties of BiFeO3 multiferroic ceramics prepared by sol–gel and spark plasma sintering techniques. Issue 6 (1st May 2016)

• Record Type: Journal Article
• Authors: Wang, Ting; Song, S.-H.; Wang, Meng; Li, J.-Q.; Ravi, M.
• Is Part Of: Ceramics international. Volume 42:Issue 6(2016)
• Page Start: 7328
• Page End: 7335
• Publication Date: 2016-05-01
• Subjects: A. Sol–gel processes -- C. Impedance -- C. Dielectric properties -- C. Electrical properties -- Multiferroic ceramics; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2016.01.129
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Phase-pure BiFeO3 powders were synthesized by sol–gel technique. Based on these powders, high-density BiFeO3 ceramics were prepared by spark plasma sintering (SPS) at 700 °C along with annealing for 2 and 4 h, respectively, at 650 °C under atmospheres of air and oxygen. X-ray diffraction analysis revealed that the 4 h-oxygen-annealed sample contained a single rhombohedral perovskite phase while the samples annealed in the other conditions contained small quantities of impurity phases besides the rhombohedral perovskite phase. The relative density of the 4 h-oxygen-annealed sample was about 96%, being apparently higher than that of the other samples. In comparison with the 4 h-air-annealed sample, the dielectric constant of the 4 h-oxygen-annealed sample was relatively higher. The activation energy for electrical conduction was about 1.17 eV for the 4 h-oxygen-annealed sample while it was about 0.98 eV for the 4 h-air-annealed sample, showing that the former would have a lower room-temperature conductivity (~2.6×10 −14 S cm −1 ) than the latter (~2.1×10 −13 S cm −1 ). It is therefore anticipated that the oxygen-annealed sample could possess better ferroelectric properties as compared to the air-annealed sample.