TY - JOUR
T1 - Sinterability, reducibility, and electrical conductivity of fast oxide-ion conductors La1.8R0.2MoWO9 (R=Pr, Nd, Gd and Y)
AU - Ge, Lin
AU - Guo, Kai
AU - Guo, Lucun
N1 - Publisher Copyright:
© 2015 Elsevier Ltd and Techna Group S.r.l.
PY - 2015/9/1
Y1 - 2015/9/1
N2 - Abstract To examine the effect of La-site substitution on the performance of the fast oxide-ion conductor β-La2MoWO9, doped La1.8R0.2MoWO9 (R=Pr, Nd, Gd and Y) electrolytes are synthesized via solid-state reaction. The structures and properties of the electrolytes are studied by X-ray diffraction, dilatometric analysis, scanning electron microscopy, and impedance spectroscopy. Pr, Nd, and Y substitutions decrease the sintering temperature and increase the average grain size. The as-sintered specimens are annealed at 873 K in humidified 25% H2-N2 to test their structural stabilities. Compared with Nd-doped and Gd-doped samples, Pr-doped and Y-doped specimens do not exhibit obvious surface degradation after reduction. Although all substitutions relatively enhance the low-temperature (<500°C) conductivity of La2MoWO9, only Pr substitution obviously increases the high-temperature conductivity of the corresponding electrolyte. The temperature dependence of La1.8R0.2MoWO9 conductivity were well fitted to an Arrhenius model below 500°C and a Vogel-Tamman-Fulcher model above 500°C.
AB - Abstract To examine the effect of La-site substitution on the performance of the fast oxide-ion conductor β-La2MoWO9, doped La1.8R0.2MoWO9 (R=Pr, Nd, Gd and Y) electrolytes are synthesized via solid-state reaction. The structures and properties of the electrolytes are studied by X-ray diffraction, dilatometric analysis, scanning electron microscopy, and impedance spectroscopy. Pr, Nd, and Y substitutions decrease the sintering temperature and increase the average grain size. The as-sintered specimens are annealed at 873 K in humidified 25% H2-N2 to test their structural stabilities. Compared with Nd-doped and Gd-doped samples, Pr-doped and Y-doped specimens do not exhibit obvious surface degradation after reduction. Although all substitutions relatively enhance the low-temperature (<500°C) conductivity of La2MoWO9, only Pr substitution obviously increases the high-temperature conductivity of the corresponding electrolyte. The temperature dependence of La1.8R0.2MoWO9 conductivity were well fitted to an Arrhenius model below 500°C and a Vogel-Tamman-Fulcher model above 500°C.
KW - A. Sintering
KW - E. Fuel cells
KW - LAMOX
KW - Solid electrolyte
KW - Structural stability
UR - http://www.scopus.com/inward/record.url?scp=84930931631&partnerID=8YFLogxK
U2 - 10.1016/j.ceramint.2015.04.127
DO - 10.1016/j.ceramint.2015.04.127
M3 - 文章
AN - SCOPUS:84930931631
SN - 0272-8842
VL - 41
SP - 10208
EP - 10215
JO - Ceramics International
JF - Ceramics International
IS - 8
M1 - 10534
ER -