Large strain with low hysteresis and its contributions in Sm-doped PYN-PMN-PT piezoceramics via MPB regulation

Abstract

Piezoelectric ceramics play a critical role in precision-driven applications; however, achieving high-strain performance often comes at the cost of increased hysteresis and compromised thermal stability. This study reports on 1.5 mol. % Sm3+-doped 0.16PYN-0.52PMN-0.32PT ceramics, with a phase structure situated near the morphotropic phase boundary, which exhibit significantly enhanced piezoelectric properties, including an enhanced piezoelectric coefficient (d33 = 710 pC/N), a large-signal piezoelectric coefficient (d33* = 885 pm/V), and an ultra-low strain hysteresis (H = 3.9%). Rayleigh analysis reveals that this optimization is primarily attributed to increased lattice distortion and a significant enhancement in the contribution of the reversible domain wall motion, accounting for 54% of the total piezoelectric response. This effectively suppresses irreversible domain wall motion, thereby reducing strain hysteresis. Furthermore, the ceramics maintain an ultrahigh unipolar strain of ≈0.22% and excellent thermal stability within the temperature range of 45–120 °C. This study systematically investigates the mechanisms underlying low-hysteresis strain behavior and proposes optimization strategies from the perspectives of phase structure regulation and domain wall behavior, offering insights for the design of high-performance piezoelectric ceramics in precision-driven applications.