A Comparative study of KNN-based piezoceramic composite synthesized by two different sintering methods

Abstract The presented work attempts to compare the electrical properties of lead-free piezoceramics 0.982(K 0.485 Na 0.485 Li 0.03 )(Nb 0.96 Sb 0.04 )O 3 -0.015Bi 0.5 Na 0.5 ZrO 3 -0.003SnO 2 (KNN-BNZ-SnO 2 ) fabricated by two different sintering techniques, namely two-step sintering method (TSS) and conventional sintering method (CS). Study of resulting ceramics using XRD profiles reveals pure perovskite form but exist distinct impacts of the two approaches of sintering on dielectric, ferroelectric and piezoelectric properties. Diffused phase transition around the Curie temperature with larger diffusivity (γ = 1.70) reveals that ceramic prepared by two-step sintering method behaves as stronger relaxor ferroelectric. Room temperature dielectric constant ( ε rt  = 2496), remanent polarization ( P r = 9.55 µC/cm 2 ) and piezoelectric coefficient ( d 33  = 288 pC/N), obtained from two-step sintering are greater than those ( ε rt  = 1502, P r = 5.53 µC/cm 2 , d 33  = 221 pC/N) of conventional sintering. This study demonstrates that two-step sintering method is a better method in comparison to conventional sintering technique in enhancing the overall performance of this composite piezoceramics.