Controlling the cation distribution and electric polarization with epitaxial strain in Aurivillius-phase Bi${}_5$FeTi${}_3$O${}_{15}$

Abstract

This work explores the impact of in-plane bi-axial (epitaxial) strain on the cation distribution and electric polarization of the Aurivillius-phase compound Bi${}_5$FeTi${}_3$O${}_{15}$ using first-principles electronic structure calculations. Our calculations indicate that the site preference of the Fe${}^{3+}$ cation can be controlled via epitaxial strain. Tensile strain enhances the preference for the inner sites within the perovskite-like layers of the Aurivillius-phase structure, whereas compressive strain favors occupation of the outer sites within the perovskite-layers, i.e., the sites close to the Bi${}_2$O${}_2$ layer. Controlling the distribution of the magnetic cations offers the possibility to control magnetic order in this magnetically dilute system. Furthermore, the magnitude of the electric polarization is strongly strain-dependent, increasing under tensile strain and decreasing under compressive strain. Analysis of the Born effective charges reveals strongly anomalous charges, both of the Bi${}^{3+}$ cations and the Ti${}^{4+}$ cations.

5 pages, 3 figures, 1 table. Submitted to Applied Physics Letters

References in corpus (6)

• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• First-principles study of spontaneous polarization in multiferroic BiFeO${}_3$
• Effect of epitaxial strain on the spontaneous polarization of thin film ferroelectrics
• Engineering multiferroism in CaMnO${}_3$
• The potentially multiferroic Aurivillius phase Bi${}_5$FeTi${}_3$O${}_{15}$: cation site preference, electric polarization, and magnetic coupling from first principles