This paper reports a systematic study of tungsten bronze morphotropic phase boundary (MPB) system Pb 2-2X-3Y/2 Ba 2x RE y K 1-x Na x Nb 5 O 15, where, x = 0.20, 0.25, 0.30, RE = Pr and Bi and y = 0.05 and their structure, microstructure, hysteresis, dielectric, piezoelectric, and Pyroelectric properties. Enhanced piezoelectric constants kp, kt, k31, d31, d33, g31, g33, [Formula: see text] as 30.8%, 47.6%, 18.9%, 57 × 10-12 C/N , 159 × 10-12 C/N , 6.89 × 10-3 mV/N , 19.23 × 10-3 mV/N , and 13.88 × 10-12 m 2/ N respectively are observed in the composition for which y = 0, and x = 0.30, which is above MPB. Also, a change in thickness, 0.0159 μm has been developed for a thickness of the sample 1.2 mm, d33 = 159 × 10-12 C/N and for an applied voltage of 100 V. The same material produces a length extension, 0.0475 μm for d31 = 57 × 10-12 C/N , l = 10 mm , t = 1.2 mm , for an applied voltage of 100 V. Thus the material may be useful for a piezoelectric transducer. Enhanced piezoelectric coefficients, d31 = 96 × 10-12 C/N and g33 = 12.95 × 10-3 mV/N are also observed in the composition for which RE = Pr and x = 0.25.
Enhancing temperature stability in potassium-sodium niobate ceramics through phase boundary and composition design
