Dopant Site Occupancy and Chemical Expansion in Rare Earth‐Doped Barium Zirconate. Issue 2 (12th December 2013)

• Record Type: Journal Article
• Authors: Han, Donglin; Shinoda, Kozo; Uda, Tetsuya; Brennecka, G.
• Is Part Of: Journal of the American Ceramic Society. Volume 97:Issue 2(2014)
• Page Start: 643
• Page End: 650
• Publication Date: 2013-12-12
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.12681
• Languages: English
• ISSNs: 0002-7820

Abstract

<abstract abstract-type="main" id="jace12681-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Rare earth‐doped BaZrO₃ is a very attractive material in electrochemical applications due to its proton conductive property. In this work, powder X‐ray diffraction patterns of BaZr_0.8M_0.2O_3−δ (M = Sc, Eu, Sm, Dy) were collected using synchrotron radiation, and also using characteristic X‐ray of Cu<italic>K</italic>α in dry and wet atmospheres at high temperature. Then, a combined interpretation of the diffraction patterns was established by using Rietveld refinement. The results revealed that an obvious lattice expansion was observed for BaZr_0.8M_0.2O_3−δ (M = Sc, Eu, Sm, Dy) in wet O₂ compared with the case in dry condition, indicating a chemical expansion effect on lattice volume by incorporating water into lattice. Eu, Sm, and Dy cations occupied both A‐ and B‐sites of BaZrO₃ crystalline lattice, whereas Sc cations were determined to occupy B‐site only. These results indicate clearly an increasing tendency toward A‐site occupation for the rare earth cations in BaZrO₃ with an increasing radius.</p> </abstract>