Study of crystal structure and protonic conduction properties of laaaoprepared by liquid synthesis method

Naoki Hamao, Naoto Kitamura, Naoya Ishida, Takashi Kamiyama, Shuki Torii, Masao Yonemura, Yasushi Idemoto

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

In order to investigate an effect of the preparation process on protonic conductivity of LaaaO we attempt to prepare the samples with x = 0.1, LaaaO by a liquid synthesis method as well as a conventional solid-phase method. Their electrical conductivities are measured from 300 to 900°C in various water vapor partial pressures, PH2O. From the result, it is found that the protonic conductivity is higher in the sample synthesized bythe liquid synthesis method compared with that by the solid-phase method. In addition, it is also indicated that the PH2O-dependence of the electrical conductivity around 600°C is more significant in the sample prepared by the liquid synthesis method. This result implies that this method enhances proton dissolution inLaaaOat 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.

Original languageEnglish
Pages (from-to)550-556
Number of pages7
JournalElectrochemistry
Volume82
Issue number7
DOIs
Publication statusPublished - 1 Jan 2014

Keywords

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

Cite this