Quasi-Elastic Neutron Scattering Reveals Fast Proton Diffusion in Ca-Doped LaPO4

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• 作者：Amal al-Wahish ; Niina Jalarvo ; Zhonghe Bi ; K. W. Herwig ; Craig Bridges ; M. P. Paranthaman ; D. Mandrus
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：September 4, 2014
• 年：2014
• 卷：118
• 期：35
• 页码：20112-20121
• 全文大小：686K
• ISSN：1932-7455

文摘

We have investigated the diffusion dynamics of protons in hydrated 4.2% Ca-doped LaPO₄, a candidate electrolyte for proton-conducting intermediate temperature fuel cells. The macroscopic and microscopic dynamics have been studied using electrochemical impedance spectroscopy (EIS) and quasi-elastic neutron scattering (QENS), respectively. The conductivity of the bulk hydrated sample was determined in the temperature range of 500鈥?50 掳C by EIS and showed a clear signature of proton conductivity with an activation energy of about 1.0 eV. The QENS experiment revealed a fast dynamical process below 500 掳C that was not observed by EIS. The activation energy of the fast proton diffusion is 0.09 eV in the temperature range from 150 掳C to 500 掳C.