Influence of La/W ratio on electrical conductivity of lanthanum tungstate with high La/W ratio
Influence of La/W ratio on electrical conductivity of lanthanum tungstate with high La/W ratio
复制标题
La/W比对高La/W比钨酸镧电导率的影响
DOI：
10.1016/j.jssc.2017.01.011
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发表时间：
2017
影响因子：
3.3
通讯作者：
Yoshito Oshima and Junichiro Otomo
中科院分区：
文献类型：
--
作者：
Gen Kojo;Yohei Shono;Hiroshi Ushiyama;Yoshito Oshima and Junichiro Otomo
采用电化学测量和量子化学计算方法研究了高La/W比钨酸镧（LWOs）的质子导电性能。通过1700℃左右的高温烧结，合成了高La/W比（6.3≤La/W≤6.7）的单相LWOs。在单相区，LWO的电导率随La/W比的增大而增大。在最佳的烧结温度和时间下合成的LWO，在最佳的La/W比下，在500℃下获得了最大的电导率2.7×10−3S cm−1,La/W=6.7。采用轻推弹性带方法进行了质子扩散势垒的密度泛函理论计算。结果表明，La位周围的质子扩散路径具有最低的质子扩散势垒。这些发现提高了我们对LWO合成和质子传导机制的理解，并为改善LWO中质子传导提供了策略。
The proton-conducting properties of lanthanum tungstates (LWOs) with high La/W ratios were investigated using electrochemical measurements and quantum chemical calculations. Single phases of LWOs with high La/W ratios (6.3≤La/W≤6.7) were synthesized by high-temperature sintering at around 1700 °C. The electrical conductivity of LWO increased with increasing La/W ratio in the single-phase region. The LWO synthesized at the optimum sintering temperature and time, and with the optimum La/W ratio gave the maximum conductivity, i.e., 2.7×10−3S cm−1with La/W=6.7 at 500 °C. Density functional theory calculations, using the nudged elastic band method, were performed to investigate the proton diffusion barrier. The results suggest that the proton diffusion paths around La sites have the lowest proton diffusion barrier. These findings improve our understanding of LWO synthesis and the proton-conducting mechanism and provide a strategy for improving proton conduction in LWOs.