Phase transition behavior and high electrostrictive strains in Bi(Li0.5Nb0.5)O3-doped lead magnesium niobate-based solid solutions

Abstract Bi(Li 0.5 Nb 0.5 )O 3 (BLN) was adopted to tailor the Curie temperature ( T C ) and the resulting ferroelectric and electrostrictive properties of solid solutions of the morphotropic phase boundary relaxor ferroelectric 0.67 Pb(Mg 1/3 Nb 2/3 )O 3 -0.33PbTiO 3 (0.67PMN-0.33 PT). The ceramic samples were synthesized by a solid reaction method, and the BLN content was set to 2.5 at.%, 5 at.%, 7.5 at.%, and 10 at.%. X-ray diffraction results suggested that BLN cannot enter the 0.67PMN-0.33 PT crystal lattice completely, resulting in the formation of a second phase (Pb 2 Ti 2 O 6 with pyrochlore structure) in all the samples. With increasing BLN content, a decrease in T C and a ferroelectric-to-relaxor transition were revealed by the dielectric and ferroelectric properties. High electric-field-induced strains of 0.167%–0.228% with low hysteresis ( Q 33 ranged from 0.150 to 0.185 m 4 /C 2 and was insensitive to temperature. Our results suggest that BLN-doped 0.67PMN-0.33 PT ceramics could have potential applications in actuator devices owing to their high strain response and ultralow hysteresis.