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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 11: (Multi)ferroic States: From Fundamentals to Applications (V)

KFM 11.2: Vortrag

Mittwoch, 19. März 2025, 10:00–10:15, H9

Tuning of ferroelectric polarization by lattice chemistry — •Ipek Efe¹, Alexander Vogel², William S. Huxter¹, Elzbieta Gradauskaite¹, Christian L. Degen¹, Marta D. Rossell², Manfred Fiebig¹, and Morgan Trassin¹ — ¹ETH Zurich — ²Empa, Switzerland

Engineering the lattice chemistry in oxide thin film systems opens up new possibilities for tuning electrostatic boundary conditions beyond the depolarizing-field tuning approaches. Controlling the formation of polarizing charged layers may stabilize highly desired polar textures such as charged domain walls and charge planes, offering great promises for future ultralow-energy-consuming oxide electronics. Here, we demonstrate lattice-chemistry engineering of perovskite oxide ferroelectrics in a heterostructure utilizing Aurivillius-type layering. We insert functional perovskite oxides, including BiFeO₃ and BaTiO₃, into the layered framework of the Aurivillius phase. By exploiting the characteristic charged interfaces present in the Aurivillius crystal structure and varying the perovskite constituent, we fine-tune the electric-dipole configurations within our composite heterostructures. Using in-situ optical second harmonic generation, we directly resolve the influence of controlled atomic-scale poling of the Aurivillius charged layers on the perovskite constituent. As a result, we achieve new properties while preserving the functionalities of the parent compounds.

Keywords: Ferroelectric thin films; Layered ferroelectrics; Polarization engineering; Aurivillius; Lattice chemistry engineering