Sodium ion conduction in sodium lanthanum zirconate ceramics prepared by spark plasma sintering
Sodium ion conduction in sodium lanthanum zirconate ceramics prepared by spark plasma sintering
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DOI：
10.1016/j.scriptamat.2021.113887
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发表时间：
2021-07
影响因子：
6
通讯作者：
N. Toyomura;George Hasegawa;Kazuma Nishimi;M. Inada;N. Enomoto;K. Hayashi
中科院分区：
文献类型：
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作者：
N. Toyomura;George Hasegawa;Kazuma Nishimi;M. Inada;N. Enomoto;K. Hayashi
通过放电等离子烧结（SPS）制备了具有斜方（Pnma）钙钛矿结构的致密陶瓷Na3xLa2/3−xZrO3−δ，并结合晶体化学研究了其Na+离子传导行为。尽管SPS技术抑制了Na的挥发，但在烧结过程中Na成分往往会部分损失，因此，钙钛矿的化学成分被限制在一个小范围内，3x= 0.32–0.35，这在与La2Zr2O7烧绿石和ZrO2的第二相平衡时是有利的。与 Na3xLa2/3−xTiO3 的同构钛酸盐衍生物中观察到的相比，Na0.32La0.48ZrO2.9 的样品表现出增强的体电导率（350 °C 下为 7.2 × 10−5S cm−1）和低得多的活化能（0.26 eV），表明通过 Zr 取代 Ti 扩展的钙钛矿晶格提供了迁移途径对于Na+离子来说足够宽。
Dense ceramics of Na3xLa2/3−xZrO3−δwith 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 La2Zr2O7pyrochlore and ZrO2. A sample with Na0.32La0.48ZrO2.9exhibits an enhanced bulk conductivity (7.2 × 10−5S cm−1at 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.