Tritium conductivity and isotope effect in proton-conducting perovskites
Tritium conductivity and isotope effect in proton-conducting perovskites
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DOI：
10.1149/1.1391911
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发表时间：
1999-06-01
影响因子：
3.9
通讯作者：
Willms, RS
中科院分区：
文献类型：
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作者：
Mukundan, R;Brosha, EL;Willms, RS
用交流阻抗法测定了SrZr0.9Yb0.1O2.95和BaCe0.9Yb0.1O2.95的氚离子电导率。这些钙钛矿的高氚导电性可能导致它们作为一种电化学膜的应用，用于从氚化气流中回收氚。这些钙钛矿和SrCe0.95Yb0.05O2.975在含氢和含氘的大气中也进行了电导率测量，以说明同位素效应。对于锆酸锶和铈酸钡样品，阻抗图由两个清晰分辨的弧线组成，即体和晶界，温度范围为50-350℃。然而，对于铈酸锶样品，体电导率的清晰分辨是不可能的，只能测量总电导率。因此，同位素效应仅在锆酸锶和铈酸钡样品中得到明确确立。体积电导率随同位素质量的增加而下降是由于传导活化能的增加伴随着指数前因子的减少。由于在温度< 350℃时，流动物质（H+、D+或T+）的浓度应保持相对恒定，因此活化能的增加直接归因于同位素迁移活化能的增加。(C) 1999电化学学会。版权所有。
The tritium ion conductivities of SrZr0.9Yb0.1O2.95 and BaCe0.9Yb0.1O2.95 have been measured by ac impedance analysis. The high tritium conductivity of these perovskites could potentially lead to their application as an electrochemical membrane for the recovery of tritium from tritiated gas streams. The conductivities of these perovskites, along with SrCe0.95Yb0.05O2.975 were also measured in hydrogen- and deuterium-containing atmospheres to illustrate the isotope effect. For the strontium zirconate and barium cerate samples, the impedance plot consists of two clearly resolved arcs, a bulk and a grain boundary are, in the temperature range 50-350 degrees C. However, for the strontium cerate sample, the clear resolution of the bulk conductivity was not possible and only the total conductivity was measurable. Thus, the isotope effect was clearly established only for the strontium zirconate and barium cerate samples. The decrease in bulk conductivity with increasing isotope mass was found to be a result of an increase in the activation energy for conduction accompanied by a decrease in the pre-exponential factor. Since the concentration of the mobile species (H+, D+, or T+) should remain relatively constant at T < 350 degrees C, this increase in activation energy is directly attributable to the increased activation energy for the isotope mobility. (C) 1999 The Electrochemical Society. All rights reserved.