Geometric parameterization of the YBaCo4O7 structure type: implications for stability of the hexagonal form and oxygen uptake

Avdeev, M; Kharton, VV; Tsipis, EV

Geometric parameterization of the YBaCo4O7 structure type: implications for stability of the hexagonal form and oxygen uptake

Date

2010-10

Authors

Avdeev, M

Kharton, VV

Tsipis, EV

Publisher

Elsevier

Abstract

We explore the stability of the hexagonal form of MBaCo4O7 cobaltites in terms of geometric characteristics of the crystal structure and Global Instability Index (GII) based on the bond-valence considerations. Mismatch between an M3+/2+ and the three-dimensional network of CoO4 tetrahedra, whether expressed using an M ionic radii or GII, is shown to essentially determine both the temperature of structural transition to an orthorhombic modification and oxygen storage properties. A number of M cations not reported in the literature are identified to be suitable for the octahedral sites in an MBaCo4O7 structure. © 2010, Elsevier Ltd.

Keywords

Oxygen, Crystal structure, Phase transformations, Cations, Valence, Stability

Citation

Avdeev, M., Kharton, V. V., & Tsipis, E. V. (2010). Geometric parameterization of the YBaCo4O7 structure type: implications for stability of the hexagonal form and oxygen uptake. Journal of Solid State Chemistry, 183(10), 2506-2509. doi:10.1016/j.jssc.2010.08.019