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

摘要

[110]-oriented barium titanate (BaTiO_3) ceramics were prepared by.templated grain growth (TGG) method using [110]-oriented BaTiO_3 platelike particles as a template and hydrothermal BaTiO_3 sphere particles with different particle sizes as a matrix. The degree of orientation along the [110] direction, F_(110), was measured using an X-ray diffraction (XRD) pattern by the Lotgering method. To obtain both a high density and a high F_(110), 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, BaTiO_3-grain-oriented ceramics with a high density of more than 96% were successfully prepared despite various F_(110) values from 0 to 98%. Scanning electron microscopy (SEM) revealed that their average grain sizes were always approximately 75 μm despite various F_(110) values and there were no anisotropic microstructures. These grain-oriented BaTiO_3 ceramics were poled at 100℃, and their piezoelectric properties were measured using a resonance-antiresonance method and a piezo d_(33) meter for d_(31) and d_(33) piezoelectric constants. As for the results, the d_(31) values were almost constant at-50 pC/N despite various F_(110) values, while the d_(33) values increased with increasing F_(110) values, and at around an F_(110) of 85%, d_(33) reached a maximum of 788 pC/N.