TY - JOUR
T1 - Effect of impurity silica on grain boundary resistance of yttrium-doped barium zirconate
AU - Imashuku, Susumu
AU - Tanaka, Takaaki
AU - Kuramitsu, Akiko
AU - Nose, Yoshitaro
AU - Uda, Tetsuya
N1 - Funding Information:
This study was supported by Industrial Technology Research Grant Program in 2006 from New Energy and Industrial Technology Development Organization (NEDO) of Japan. A part of this study was also financially supported by Research Fellowship for Young Scientists from JSPS (202005).
PY - 2010
Y1 - 2010
N2 - The concentrations of impurities in BaZr0.85Y 0.15O3-δ were qualitatively measured by GD-MS, and the concentrations of carbon, nitrogen, sodium, silicon, sulfur, chlorine, hafnium, and platinum were found to be more than 100 ppm. Among these identified impurities, we investigated the influence of sodium and silicon on grain boundary resistance of BaZr0.85Y0.15O3-δ. It was found that silica or silicate precipitated at grain boundary of BaZr0.85Y0.15O3-δ and prevented the proton conduction of BaZr0.85Y0.15O3-δ at the grain boundary, but sodium did not affect either bulk or grain boundary resistance. Also, we investigated which steps of the applied procedure causes the increase in the silicon concentration of BaZr0.85Y 0.15O3-δ during the synthesis process of the widely-used solid state reaction method. Drying the powder in atmospheric air and using the heated glass flask were found to be major problems. With this knowledge, we reduced the silicon concentration of sintered BaZr 0.85Y0.15O3-δ to 120 ppm.
AB - The concentrations of impurities in BaZr0.85Y 0.15O3-δ were qualitatively measured by GD-MS, and the concentrations of carbon, nitrogen, sodium, silicon, sulfur, chlorine, hafnium, and platinum were found to be more than 100 ppm. Among these identified impurities, we investigated the influence of sodium and silicon on grain boundary resistance of BaZr0.85Y0.15O3-δ. It was found that silica or silicate precipitated at grain boundary of BaZr0.85Y0.15O3-δ and prevented the proton conduction of BaZr0.85Y0.15O3-δ at the grain boundary, but sodium did not affect either bulk or grain boundary resistance. Also, we investigated which steps of the applied procedure causes the increase in the silicon concentration of BaZr0.85Y 0.15O3-δ during the synthesis process of the widely-used solid state reaction method. Drying the powder in atmospheric air and using the heated glass flask were found to be major problems. With this knowledge, we reduced the silicon concentration of sintered BaZr 0.85Y0.15O3-δ to 120 ppm.
KW - Barium zirconate
KW - Conductivity
KW - Grain boundary
KW - Impurities
KW - Proton
KW - Silicon
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U2 - 10.1515/HTMP.2010.29.5-6.339
DO - 10.1515/HTMP.2010.29.5-6.339
M3 - Article
AN - SCOPUS:78651381143
SN - 0334-6455
VL - 29
SP - 339
EP - 346
JO - High Temperature Materials and Processes
JF - High Temperature Materials and Processes
IS - 5-6
ER -