5 years ago

Oxygen Ion Transport and Effects of Doping in Ba3Ti3O6(BO3)2

Oxygen Ion Transport and Effects of Doping in Ba3Ti3O6(BO3)2
Eric Quarez, Jean-Marie Doux, Olivier Joubert, Khang Hoang
We report for the first time a combined experimental and computational study of oxygen ion transport and the effects of doping in Ba3Ti3O6(BO3)2, a promising oxyborate for solid-oxide fuel cell applications. Undoped and doped samples were prepared by solid-state reaction and characterized using X-ray diffraction and electrochemical impedance spectroscopy. We find that the undoped sample already has a conductivity level that is quite high, about 1.46 × 10–4 S cm–1 at 700 °C in air. Partial replacement of Ba2+ or Ti4+ by subvalent elements, Ba3–xAxTi3O6(BO3)2 (A = Na+, K+) and Ba3Ti3–xMxO6 (BO3)2 (M = Mg2+, In3+, Sb3+), leads to reduced conductivity, whereas partial replacement of Ti4+ by supervalent elements, Ba3Ti3–xMxO6(BO3)2 (M = Nb5+, Ta5+), increases the conductivity. The measured activation energy is in the range 0.99–1.09 eV for the doped samples (compared to 1.02 eV of the undoped one). The transport properties can be understood in terms of the presence of oxygen and barium vacancies in high concentrations as well as oxygen interstitials as observed in hybrid density-functional defect calculations.

Publisher URL: http://dx.doi.org/10.1021/acs.chemmater.7b01831

DOI: 10.1021/acs.chemmater.7b01831

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.