Fluctuations and Landau-Devonshire expansion for barium titanate

The experimentally observed temperature dependence of the quartic coefficients in the Landau-Devonshire expansion for BaTiO3 is naturally accounted for within a proper fluctuation model. It is explained, in particular, why one of the quartic coefficients varies with temperature above T-c, while the second is constant. It is argued that the tetragonal phase in BaTiO3 exists essentially due to thermal fluctuations, while the true Landau-Devonshire expansion with temperature-independent coefficients favors the rhombohedral ferroelectric phase. (C) 2002 MAIK "Nauka / Interperiodica".


Published in:
Jetp Letters, 75, 8, 410-414
Year:
2002
ISSN:
0021-3640
Note:
Sokolov, Ai St Petersburg Electotech Univ, St Petersburg 197376, Russia St Petersburg Electotech Univ, St Petersburg 197376, Russia Ecole Polytech Fed Lausanne, CH-1015 Lausanne, Switzerland
561WY
Times Cited:0
Cited References Count:12
Laboratories:




 Record created 2006-08-21, last modified 2018-03-17


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