## Abstract

The speed of D-H replacement in D-implanted BaCe_{1-X}Y _{X}O_{3-δ} and SrCe_{1-X}Yb_{X}O _{3-δ}, exposed to H_{2}O vapor at room temperature has been studied as a function of X by use of the ERD technique with 1.7 MeV He ^{+} ion beam. The decay curve of D and growth curve of H in the specimens have been measured as a function of exposure time, and the decay constants of D, namely the D-H replacement speeds, have been obtained by fitting the experimental curves to the theoretical curves of D decay and H growth, which are derived from the mass balance equations described on the one-way diffusion model for the D-H replacement: absorption of H^{+} due to splitting of H_{2}O physisorbed at the surface, diffusion of H ^{+} and emission of D implanted in the traps as HD molecule due to bulk recombination of H^{+} and subsequent trapping of H^{+} in the vacant trap. It is found for both specimens that the decay constants of D, proportional to the absorption coefficient and the molecular formation coefficient of HD, increase, and after a maximum at X = 0.05-0.1 decrease as X increases, and the absolute experimental values for BaCe_{1-X}Y _{X}O_{3-δ} are larger almost by an order of magnitude than those of SrCe_{1-X}Yb_{X}O_{3-δ}. These experimental results are discussed in terms of the one-way diffusion model on D-H replacement and water splitting model at the surface.

Original language | English |
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Pages (from-to) | 1573-1577 |

Number of pages | 5 |

Journal | Surface and Interface Analysis |

Volume | 38 |

Issue number | 12-13 |

DOIs | |

Publication status | Published - 2006 Dec 1 |

## Keywords

- Hydrogen gas emission
- Hydrogen isotopes replacement
- Ion beam analysis
- Oxide ceramics
- Water splitting

## ASJC Scopus subject areas

- Chemistry(all)
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry