TY  - JOUR
AU  - Ivanova, Mariya
AU  - Meulenberg, Wilhelm A.
AU  - Palisaitis, Justinas
AU  - Sebold, Doris
AU  - Solís, Cecilia
AU  - Ziegner, Mirko
AU  - Serra, Jose M.
AU  - Mayer, Joachim
AU  - Hänsel, Michael
AU  - Guillon, Olivier
TI  - Functional properties of La$_{0.99}$X$_{0.01}$Nb$_{0.99}$Al$_{0.01}$O$_{4−δ}$ and La$_{0.99}$X$_{0.01}$Nb$_{0.99}$Ti$_{0.01}$O$_{4−δ}$ proton conductors where X is an alkaline earth cation
JO  - Journal of the European Ceramic Society
VL  - 35
IS  - 4
SN  - 0955-2219
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2015-05640
SP  - 1239 - 1253
PY  - 2015
AB  - Lanthanum niobates with general formulas of La0.99X0.01Nb0.99Al0.01O4−δ and La0.99X0.01Nb0.99Ti0.01O4−δ (X = Mg, Ca, Sr or Ba) were synthesized via the conventional solid state reaction. Specimens with relative density above 96% were produced after sintering. Structural and phase composition studies revealed predominant monoclinic Fergusonite structure for the majority of samples. SEM and TEM studies elucidated the effect of the used dopant combinations on grain growth, micro-crack formation and secondary phase formation. Results from microstructural study were correlated to the grain interior and grain boundary conductivities for selected samples (La0.99Sr0.01Nb0.99Al0.01O4−δ and La0.99Sr0.01Nb0.99Ti0.01O4−δ). The majority of co-doped niobates exhibited appreciable protonic conductivity under humid atmospheres at intermediate temperatures. Sr- or Ca-doped compounds displayed the highest total conductivities with values for LSNA equal to 6 × 10−4 S/cm and 3 × 10−4 S/cm in wet air and in wet 4% H2–Ar (900 °C), respectively. Additionally, thermal expansion was studied to complete functional characterization of co-doped LaNbO4.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000348084300012
DO  - DOI:10.1016/j.jeurceramsoc.2014.11.009
UR  - https://juser.fz-juelich.de/record/255478
ER  -