2012/04/29 by Anna N. Morozovska, A. N. Morozovska, E. A. Eliseev +6 · 24 citations
Chemistry · Engineering · Materials Science · Physics and Astronomy · #Acoustic Wave Resonator Technologies #Chemistry #Composite material #Condensed matter physics #Coupling (piping) #Dielectric #Ferroelectric and Piezoelectric Materials #Ferroelectricity #Geophysics and Sensor Technology #Materials science #Nanotechnology #Optoelectronics #Phase (matter) #Phase diagram #Physics #Pyroelectricity #Thin film #cond-mat.mtrl-sci
paper · pdf · doi:10.1063/1.4752397
published in Journal of Applied Physics 112(6) (American Institute of Physics) · 35 pages, 9 figures, 1 appendix, 1 table
arxiv created 2012/04/29 · openalex publication_date 2012/09/15 · arxiv updated 2015/06/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
The influence of the flexoelectric and rotostriction coupling on the phase diagrams of ferroelastic-quantum paraelectric SrTiO3 films was studied using Landau-Ginzburg-Devonshire theory. The phase diagrams in coordinates temperature–film thickness were calculated for different epitaxial misfit strains. Tensile misfit strains stimulate appearance of the spontaneous out-of-plane structural order parameter (displacement vector of an appropriate oxygen atom from its cubic position) in the structural phase. Compressive misfit strains stimulate appearance of the spontaneous in-plane structural order parameter. Gradients of the structural order parameter components, which inevitably exist in the vicinity of film surfaces due to the termination and symmetry breaking, induce improper polarization and pyroelectric response via the flexoelectric and rotostriction coupling mechanism. Flexoelectric and rotostriction coupling results in the roto-flexoelectric field that is antisymmetric inside the film, small in the central part of the film, where the gradients of the structural parameter are small, and maximal near the surfaces, where the gradients of the structural parameter are highest. The field induces improper polarization and pyroelectric response. Penetration depths of the improper phases (both polar and structural) can reach several nm from the film surfaces. An improper pyroelectric response of thin films is high enough to be registered with planar-type electrode configurations by conventional pyroelectric methods.