Lead barium potassium sodium niobate ceramics for piezoelectric applications

This paper reports a systematic study of tungsten bronze morphotropic phase boundary (MPB) system Pb_2-2X-3Y/2Ba_2xRE_yK _1-xNa_xNb₅O₁₅, 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 k_p, k_t, k₃₁, d ₃₁, d₃₃, g₃₁, g₃₃, S ₁₁^E 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 m²/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.