Piezoelectric, pyroelectric, dielectric and ferroelectric properties of Ba0.3Na0.7Ti0.3Nb0.7O3

The ferroelectric, piezoelectric, and pyroelectric properties of Ba(1-x)Na(x)Ti(1-x)Nb(x)O(3) with x=0.70 (BTNN0.70) lead-free ceramic were investigated. Polycrystalline sample with composition BTNN0.70 was prepared by using conventional dry ceramic technique. Sample was sintered at 1250 degrees C for 3 h under oxygen showed perovskite structure with high densities 4.92 g/cm(3) (similar to 96% as relative density). X-ray analysis confirmed the formation of single-phase compound with cubic crystal structure. Dielectric properties were studied in detail as a function of frequency and temperature. From temperature variation of dielectric constant, Curie temperature (T(C)) was determined. Discussion on hysteresis behavior for the sample at room temperature is presented. An essential relation between the piezoelectric properties and the ferroelectric nature of the ceramics was detected. The piezoelectric and pyroelectric coefficients of the ceramic were studied as a function of temperature. (c) 2007 American Institute of Physics.