Berlin 2018 – scientific programme

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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 27: Postersession KFM

KFM 27.3: Poster

Thursday, March 15, 2018, 15:00–17:00, Poster E

Domain evolution in a Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 piezoceramic studied by piezoresponse force microscopy — •Xijie Jiang, Na Liu, Robert Stark, and Christian Dietz — Technische Universität Darmstadt, Alarich-Weiss-Str. 16, Darmstadt, Germany

Lead-free (1-x)Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 (BZT- xBCT) ceramics have drawn special attention to researchers because of their outstanding dielectric and electromechanical properties, competitive to lead zirconate titanate (PZT). In particular, BZT-0.5BCT was reported to have a piezoelectric coefficient of 620 pC/N explained by the existence of a triple point close to room temperature. However, the fundamental mechanisms behind the functionality of this ferroelectric are not completely understood. Here, we use piezoresponse force microscopy (PFM) to observe the domain evolution of a BZT-0.5BCT ceramic while changing the temperature and the applied voltage between tip and sample. In the initial state, the sample exhibits a combination of wedge-shaped and lamellar domains. During the increase of the applied voltage to +30 V, the observed area formed a single domain state. Subsequently decreasing the applied voltage step-wise to -30 V and increasing back to 0 V caused the sample to form wedge-shaped and lamellar domain again. Thus, the sample reversibly transforms from a multi-domain to a single-domain state during a complete poling cycle. During heating to 60 ^∘C, most wedge-shaped domains transformed to lamellar domains and the orientation of the domain configuration was partially reversed.