Preparation of [110] Grain Oriented Barium Titanate Ceramics by Templated Grain Growth Method and Their Piezoelectric Properties

Abstract

[110]-oriented barium titanate (BaTiO3) ceramics were prepared by templated grain growth (TGG) method using [110]-oriented BaTiO3 platelike particles as a template and hydrothermal BaTiO3 sphere particles with different particle sizes as a matrix. The degree of orientation along the [110] direction, F110, was measured using an X-ray diffraction (XRD) pattern by the Lotgering method. To obtain both a high density and a high F110, the preparation conditions were optimized as functions of matrix particle size, volume fraction of the template to the matrix, and sintering temperature. As for the results, BaTiO3-grain-oriented ceramics with a high density of more than 96% were successfully prepared despite various F110 values from 0 to 98%. Scanning electron microscopy (SEM) revealed that their average grain sizes were always approximately 75 µm despite various F110 values and there were no anisotropic microstructures. These grain-oriented BaTiO3 ceramics were poled at 100 °C, and their piezoelectric properties were measured using a resonance–antiresonance method and a piezo d33 meter for d31 and d33 piezoelectric constants. As for the results, the d31 values were almost constant at -50 pC/N despite various F110 values, while the d33 values increased with increasing F110 values, and at around an F110 of 85%, d33 reached a maximum of 788 pC/N.