Effect of flux on the structure and micro-morphology of inorganic proton conductor BaZrO₃

The inorganic proton conductor BaZrO3 was prepared by high solid-state reaction. The effect of flux on the synthesis temperature and microstructure of the material was investigated. The BaZrO3 single phase can be synthesized at 1500 ℃ for 8 h by adding LiF and Li2CO3 as flux. The crystallinity of the sample which used LiF as flux was much higher than that of the sample which used Li2CO3 as flux. The Rietveld-XRD data showed that the sample had good crystallinity. The band gap of the sample was 3.236 eV. The micro-morphology was changed by adding the flux. The sample used LiF as flux had smaller particle size, fewer aggregations and good dispersion. The small particles were separated out at the grain boundary, when the mass fraction of the flux was more than 8%. These small particles had potential to increase the proton conductivity.