Study of Crystal Structure and Protonic Conduction Properties of La0.9Ba1.1GaO4-delta Prepared by Liquid Synthesis Method

作者：Hamao Naoki; Kitamura Naoto^*; Ishida Naoya; Kamiyama Takashi; Torii Shuki; Yonemura Masao; Idemoto Yasushi

来源：Electrochemistry, 2014, 82(7): 550-556.

DOI：10.5796/electrochemistry.82.550

• Protonic Conductor
• Neutron Diffraction
• Rietveld Method
• Maximum Entropy Method

In order to investigate an effect of the preparation process on protonic conductivity of La1-xBa1+xGaO4-delta, we attempt to prepare the samples with x = 0.1, La0.9Ba1.1GaO4-delta, by a liquid synthesis method as well as a conventional solid-phase method. Their electrical conductivities are measured from 300 to 900 degrees C in various water vapor partial pressures, P-H2O center dot From the result, it is found that the protonic conductivity is higher in the sample synthesized by the liquid synthesis method compared with that by the solid-phase method. In addition, it is also indicated that the P-H2O-dependence of the electrical conductivity around 600 degrees C is more significant in the sample prepared by the liquid synthesis method. This result implies that this method enhances proton dissolution in La0.9Ba1.1GaO4-delta at least around the temperature range. To investigate a crystal structure change by the synthesis method, we perform powder neutron diffraction measurements. The Rietveld and maximum entropy method (MEM) analyses demonstrate that nuclear density of the proton is clearly observed between neighboring O3 sites, and suggest that the liquid synthesis method makes a site occupancy of proton higher.

• 出版日期2014-7