TY - JOUR
T1 - Sodium ion conduction in sodium lanthanum zirconate ceramics prepared by spark plasma sintering
AU - Toyomura, Naoto
AU - Hasegawa, George
AU - Nishimi, Kazuma
AU - Inada, Miki
AU - Enomoto, Naoya
AU - Hayashi, Katsuro
N1 - Funding Information:
This work was supported by Grant-in-Aid for for Scientific Research on Innovative Areas (No. JP16H06440) from MEXT, Japan, scientific research (No. 19H00828) from JSPS, Japan, and NEDO feasibility program (No. 19B301X) from NEDO, Japan.
Publisher Copyright:
© 2021
PY - 2021/7/15
Y1 - 2021/7/15
N2 - Dense ceramics of Na3xLa2/3−xZrO3−δ with orthorhombic (Pnma) perovskite structure have been prepared by spark plasma sintering (SPS) to investigate their Na+ ion conducting behaviors combining with crystal chemistry. Despite of suppressed Na volatilization owing to the SPS technique, the Na component tends to be partially lost during sintering, and consequently, the chemical composition of perovskite is limited to a small range, 3x = 0.32–0.35, which is favored under an equilibration with secondary phases of La2Zr2O7 pyrochlore and ZrO2. A sample with Na0.32La0.48ZrO2.9 exhibits an enhanced bulk conductivity (7.2 × 10−5 S cm−1 at 350 °C) and a much lower activation energy (0.26 eV) as compared with those observed in isostructural titanate-derivative of Na3xLa2/3−xTiO3, indicating that the expanded perovskite lattice by the Zr-substitution for Ti offers migration pathways wide enough for Na+ ion.
AB - Dense ceramics of Na3xLa2/3−xZrO3−δ with orthorhombic (Pnma) perovskite structure have been prepared by spark plasma sintering (SPS) to investigate their Na+ ion conducting behaviors combining with crystal chemistry. Despite of suppressed Na volatilization owing to the SPS technique, the Na component tends to be partially lost during sintering, and consequently, the chemical composition of perovskite is limited to a small range, 3x = 0.32–0.35, which is favored under an equilibration with secondary phases of La2Zr2O7 pyrochlore and ZrO2. A sample with Na0.32La0.48ZrO2.9 exhibits an enhanced bulk conductivity (7.2 × 10−5 S cm−1 at 350 °C) and a much lower activation energy (0.26 eV) as compared with those observed in isostructural titanate-derivative of Na3xLa2/3−xTiO3, indicating that the expanded perovskite lattice by the Zr-substitution for Ti offers migration pathways wide enough for Na+ ion.
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U2 - 10.1016/j.scriptamat.2021.113887
DO - 10.1016/j.scriptamat.2021.113887
M3 - Article
AN - SCOPUS:85103686208
SN - 1359-6462
VL - 200
JO - Scripta Materialia
JF - Scripta Materialia
M1 - 113887
ER -