Sintering of Fe-doped Bi0.5Na0.5TiO3 at <1000 °C

• Published in: Materials letters 2007-06, Vol.61 (14-15), p.2986-2989
• Main Authors: Watcharapasorn, A., Jiansirisomboon, S., Tunkasiri, T.
• Format: Article
• Language: English
• ISSN: 0167-577X
• DOI: 10.1016/j.matlet.2006.10.059

Fe-doped Bi0.5Na0.5TiO3 ceramics with Fe-ion content varying from 0 to 0.15 at% were prepared by a conventional solid state reaction method. The sintering temperature was between 850 and 1000 C. XRD patterns showed that all produced ceramics were single phase with a rhombohedral structure. SEM micrographs of the ceramics showed a dramatic change in densification behaviour as a result of Fe-ion doping. At 850 C, the undoped BNT ceramic had a very porous structure. As the Fe-ion concentration increased, the ceramics showed denser microstructures and, for the sample containing 0.15 at% Fe, a very dense grain structure with almost no porosity was obtained. This agreed well with the measured density, whose value increased with increasing Fe content. The relative density of at least 95% was achieved in 0.15 at% Fe-doped BNT ceramics, even when it was sintered at 850 C. Increasing the sintering temperature only increased the grain size without appreciably affecting its density. The results showed that addition of Fe2O3 in BNT could help improve the densification process and significantly reduce the sintering temperature of BNT ceramics. 24 refs.