Microstructure of Barium Cerate-Zirconate Ceramics Prepared by a Two-Step Sintering Technique

Abstract:

Ceramic materials based on cerate-zirconates have potential application as a solid electrolyte in electrochemical devices such as fuel cells and hydrogen sensors. To become a good electrolyte, the material must exhibits high density sample with homogenize grain size. In this study, we systematically investigated the microstructure of Ba (Ce,Zr)O₃ pellet as a function of sintering temperature. The calcined powder was compressed to become a pellet using hydraulic press with pressure of 5 tons for 5 min. Two-step sintering (TSS) process was applied for the densification of Ba (Ce,Zr)O₃ pellet. The first temperature profile was fixed at T₁ = 1400°C and the second temperature profile was varied from T₂ = 1150°C, 1200°C, 1250°C, 1300°C and 1350°C, respectively. The sintered sample at T₂ = 1350°C showed the highest density compared to others. Its relative density was 82.50%. The lowest density was 64.38% for the sintered sample at T₂ = 1150°C. However, the densification of pellet showed an irregular behavior at T₂ = 1300°C. It might be related to the de-densification phenomenon due to the presence of carbonate species in the calcined powder. Microstructure of the fracture sintered pellet as observed by a scanning electron microscope (SEM) showed the grain size of the samples was in the range of 149.2–336.4 nm. For a comparison, green pellet and pellet prepared with conventional sintering step (CSS) were also discussed in this study.

• Periodical: Materials Science Forum (Volume 846)
• Pages: 199-204
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.846.199
• Online since: March 2016
• Authors: Nurul Wahida Othman, Nafisah Osman*, Azliana Ramli, Suhaida Dila Safian
• Keywords: Ba(Ce,Zr)O₃, De-Densification, SEM, Two-Step Sintering

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