Crystal/defect structures and phase stability in Ba hexaaluminates

Journal Article · Thu Feb 01 04:00:00 EST 1996 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1996.0039· OSTI ID:223725

Park, J G; Cormack, A N ^[1]

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1. Alfred Univ., NY (United States)

Computer atomistic simulation techniques have been used to investigate the crystal chemistry, defect structures, and phase relationships in Ba hexaaluminates. Equilibrated lattice energies for several structural models, proposed to explain the nonstoichiometries of Ba hexaaluminates, have been calculated and suggest that Ba hexaaluminate in the magnetoplumbite structure is unstable compared to nonstoichiometric {beta}-alumina type structures. The lack of superstructure in phase is explained by the very small difference in lattice energies between the structures in which the defect complex of this phase is differently arranged. The author`s calculations also suggest that the most appropriate structural model for phase II is one which includes both triple Reidinger defects and barium interstitials inside the spinel blocks from the viewpoints of both energy and crystal symmetry.

• OSTI ID: 223725
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 121; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINATES
BARIUM COMPOUNDS
COMPUTERIZED SIMULATION
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
PHASE STUDIES
STOICHIOMETRY