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キーワード:
ab initio calculations; LacSr(1-c)MnO3; thermodynamic stability; effective mixing interatomic potential; concentration wave theory; internal formation energy
要旨:
Two different types of ab initio electronic and atomic structure
calculations for ordered solid solutions are combined with solid
solution thermodynamics in a study of the Sr-doped LaMnO3. Unlike Ba in
the isostructural (Sr,Ba)TiO3, Sr aggregation in the LaMnO3 matrix
potentially leading to decomposition into heterogeneous mixture of
LaMnO3 and SrMnO3 phases is energetically unfavorable. We demonstrate
that for a particular solid solution with 12.5% Sr the order-disorder
transition occurs only at very high temperatures otherwise Sr is
supposed to be periodically distributed in the LaMnO3 matrix. (c) 2005
Elsevier B.V. All rights reserved.
