Structure and electrical properties of Bi1/2Na1/2TiO3-based lead-free piezoelectric ceramics

摘要

Lead-free piezoelectric ceramics (1 - x)(0.935Bi(1/2)Na(1/2)TiO(3)-0.065BaTiO(3))-xAl(6)Bi(2)O(12) (BNT-BT6.5-xAB, with x = 0-0.020) were prepared using a conventional solid-state reaction method and the crystal structure and electrical properties were systematically investigated. For all BNT-BT6.5-xAB ceramics form the pure perovskite phase structure, SEM-analysis revealed an increase first and then a decrease in the grain size with increasing AB content with no obvious change in grain morphology. Appropriate AB doping into BNT-BT6.5 ceramics induces the enhancement of piezoelectric and ferroelectric properties. Improved P-r = 32.8 mu C cm(-2), low E-c of 18.2 kV cm(-1), and high d(33) = 234 pC N-1 were observed at x = 0.005. Furthermore, electric field-induced strain was enhanced to its maximum value (S-max = 0.33%) with normalized strain (d(33)(*) = S-max/E-max = 413 pm V-1) at an applied electric field of 80 kV cm(-1) for x = 0.010. The enhanced strain can be attributed to the coexistence of ferroelectric and relaxor ferroelectric phases. It is obvious that this piezoceramic is promising candidate for lead-free piezoceramics and can be used in practical applications.