Jump to main content
Jump to site search

Issue 16, 2012
Previous Article Next Article

Oxygen-deficiency-induced 6H-polymorph of hexagonal perovskite Ba4YMn3O11.5−δ: synthesis, structure and properties

Author affiliations

Abstract

The 12-layer hexagonal perovskite Ba4YMn3O11.5 (R[3 with combining macron]m, referred to as 12R) was transformed to a 6-layer mixed valent Mn3+/4+ hexagonal perovskite Ba4YMn3O10.7 (P63/mmc, referred to as 6H) via a partial-reduction in a N2 flow. This phase transformation between the 12R and 6H phases is redox-reversible. In contrast with the 12R-type Ba4YMn3O11.5 structure containing c-BaO2.75 and h-BaO3 layers with a (cchh)3 stacking, the 6H-type Ba4YMn3O10.7 structure consists of the cubic (c) BaO2.87 and hexagonal (h) BaO2.33 layers with a (cch)2 stacking, showing a preference of oxygen vacancy distribution in the hexagonal layers over the cubic layers. The h-BaO2.33 layer in the 6H-type Ba4YMn3O10.7 transforms two-thirds of face-sharing octahedral Mn2O9 dimers into edge-sharing pyramidal Mn2O8 units, sharing corners with Y octahedra/pyramids. Impedance measurements suggested that the 6H-type material is insulating with a bulk electrical resistivity of ∼107 Ω cm at 303 K, significantly higher than that for the 12R-type Ba4YMn3O11.5 by ∼4 orders of magnitude.

Graphical abstract: Oxygen-deficiency-induced 6H-polymorph of hexagonal perovskite Ba4YMn3O11.5−δ: synthesis, structure and properties

Back to tab navigation

Supplementary files

Publication details

The article was received on 14 Nov 2011, accepted on 22 Feb 2012 and first published on 16 Mar 2012


Article type: Paper
DOI: 10.1039/C2JM15845K
J. Mater. Chem., 2012,22, 8103-8109

  •   Request permissions

    Oxygen-deficiency-induced 6H-polymorph of hexagonal perovskite Ba4YMn3O11.5−δ: synthesis, structure and properties

    X. Kuang, H. Zhu, M. Allix, C. A. Bridges, M. J. Rosseinsky and Y. Li, J. Mater. Chem., 2012, 22, 8103
    DOI: 10.1039/C2JM15845K

Search articles by author

Spotlight

Advertisements