화학공학소재연구정보센터
Journal of the American Ceramic Society, Vol.102, No.6, 3477-3487, 2019
Composition-driven broad phase boundary for optimizing properties and stability in lead-free barium titanate ceramics
A new piezoelectric system of (1-x-y)BaTiO3-yCaZrO(3)-xBaSnO(3) (BT-yCZ-xBS) was designed to achieve enhanced piezoelectric/strain properties and temperature stability. First, the relationships between composition, phase, and electrical properties are systematically investigated. The broad phase boundary with successive rhombohedral-orthorhombic (R-O) and orthorhombic-tetragonal (O-T) was obtained in 0.04x0.05 and 0.04y0.07 by tailoring the relationship of composition and phase structure, confirmed by X-ray diffraction, temperature-dependent dielectric constants, and Raman spectra. The optimized piezoelectric coefficient of d(33)=560pC/N, high strain of >0.20%, and large converse piezoelectric coefficient of d(33)*=1170pm/V were realized. Second, the optimized piezoelectricity both demonstrate a stable performance with fluctuation <8% for d(33)* and 20% for d(33) between 22 and 60 degrees C since the broad phase boundary is exhibited in this temperature range. We believe that this work is a successful example to optimize piezoelectric properties and enhance the stability for piezoceramics.