Piezoelectric (NaK)NbO₃ ceramics for ultrasonic delay line applications

Abstract

Solid solutions of Na_x K_x-3y R_y NbO₃ where x = 0.5, y = 0.05 and R = Sm, Ce have been prepared by powder-metallurgical technique. Lattice parameters were determined from X-ray studies. The effect of rare-earths on the piezoelectric and ferroelectric properties of (NaK)NbO₃ ceramics have been investigated. Electromechanical coupling coefficients are measured using resonance and antiresonance technique. The quality mechanical factor(Q_m) and frequency constant (N_p) are found to be higher for Ce³⁺ composition.