Electrical properties and relaxor behavior of 0.995(K0.5Na0.5)0.95Li0.05(Nb0.95Sb0.05)O3-0.005BaTiO3 lead-free piezoelectric ceramics

摘要

The new lead-free ferroelectrics with composition of 0.995[(K0.5Na0.5)0.95Li0.05](Nb0.95Sb0.05)O3-0.005BaTiO3 (0.995KNLNS-0.005BT) were prepared by using normal sintering method, and the ferroelectric relaxor behavior and electrical properties of the ceramics were systematically studied. The ceramics exhibit typical ferroelectric relaxor behavior, that is, the dielectric peaks become increasingly broad, and the temperature of the maximum dielectric constant is shifted to higher temperature with the increasing frequency. The dielectric relaxor behavior follows the modified Curie-Weiss law. The relaxor behavior of the ceramics should be attributed to the cationic disorder induced by both of the A-sites and B-sites substitutions. The 0.995KNLNS-0.005BT ceramics also exhibit good piezoelectric properties with d33 of 269 pC/N, kp of 0.50, ɛr of 1371, tan δ of 0.03, TC of 349 °C, Pr of 22.4 µC/cm², and Ec=15.3 kV/cm.