Variation in phase diagrams of strained (011) epitaxial BaTiO3 thin films

• Published in: Physica. B, Condensed matter Vol. 540; pp. 43 - 50
• Main Authors: Wang, Fei, Ma, Wenhui
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2018; Elsevier BV
• Subjects: Anisotropy; Barium titanates; Coefficient of variation; Computation; Dependence; Elastic properties; Electrostriction; Epitaxial strain; Ferroelectric materials; Ferroelectric thin films; Ferroelectricity; Ferroelectrics; Free energy; Phase diagrams; Phase stability; Phase transition; Phase transitions; Phenomenological theory; Plane strain; Substrates; Thin films; Phenomenological theory; Epitaxial strain; Ferroelectric thin films; Phase transition
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2018.04.021

Phenomenological theory based on sixth-order and eighth-order potentials are used to investigate the effect of variation in free energy coefficients and material constants on phase stability of single-domain (011)-oriented epitaxial BaTiO3 subject to both biaxial and uniaxial substrate constraints. Relative size of a variety of ferroelectric regions in the computed misfit strain phase diagrams is systematically examined. The computed Curie phase transition and subsequent polarization rotation and formation of low-symmetry monoclinic structures are dependent on the selection of potentials and variation in electrostrictive and elastic constants, and such dependence is found to be closely associated with in-plane strain anisotropy. •For (011) epitaxial film, new phase transition forbidden in (001) film is allowed.•Misfit strain phase diagrams are computed using both 6th- and 8th-order potentials.•Effect of variation in material constants on phase stability is investigated.