Computer simulation of the structural phase transitions in thin ferroelectric films

• Published in: Journal of advanced dielectrics Vol. 7; no. 1; pp. 1750004 - 1750004-5
• Main Authors: Maksimova, O. G., Maksimov, A. V., Baruzdina, O. S.
• Format: Journal Article
• Language: English
• Published: Singapore World Scientific Publishing Company 01-02-2017; World Scientific Publishing Co. Pte., Ltd; World Scientific Publishing
• Subjects: Boundary conditions; Computer simulation; Depolarization; depolarizing field; Ferroelectric materials; Ferroelectricity; Ferroelectrics; Film thickness; Free surfaces; Heisenberg model; Mathematical analysis; Order parameters; orientation order; Phase transitions; structural transition; Surface layers; Temperature; Thin films; Transition points; Heisenberg model; Ferroelectrics; depolarizing field; orientation order; structural transition; thin films
• ISSN: 2010-135X; 2010-1368
• DOI: 10.1142/S2010135X17500047

The influence of free surface and depolarizing field on structural phase transitions in thin ferroelectric films from an ordered state to a disordered one is investigated. The dependences of the order parameter on the distance from the free film surface are calculated. It is shown that with the presence of the depolarizing field and in its absence, the effective thickness of the surface layer depends on the temperature. Nearby the phase transition point, the thickness increases indefinitely. Calculations considering depolarizing field showed that the phase transition points for the bulk ferroelectrics and the film under given boundary conditions coincide. Also shown that in the absence of depolarizing field with mixed boundary conditions, the film thickness does not affect the order parameter, and in presence of the field, this influence is observed.