Magnetoelectric coupling in Sm substituted 0.67BiFeO3- 0.33BaTiO3 ceramics

0.67(Bi 1- x Sm x )FeO 3 -0.33BaTiO 3 ( x = 0.00 ~ 0.12) ceramics were prepared by a standard solid-state sintering method. Effects of Sm substitution on the structure, dielectric and multiferroic properties in 0.67BiFeO 3 -0.33BaTiO 3 ceramics were investigated. Sm substitution destabilized the R 3 c phase, and deviated the symmetry of the present ceramics from the morphotropic phase boundary of R 3 c + Pm -3 m to Pm -3 m + P 4 mm . With increasing x , enhanced relaxor behaviors were observed with broaden dielectric peaks, and the slimmer P - E hysteresis loops. According to the Raman analysis and temperature dependence P - E hysteresis loops, all the compositions shown relaxor ferroelectricity with local nano-polar domains or clusters, while the domain size and distribution dominated the enhanced relaxor behaviors. Due to change of symmetry and hence the breaking of the spiral cycloidal spin structure of R 3 c phase, the weak ferromagnetic state with obvious macroscopic remnant magnetization was observed. Noticeable magnetoelectric (ME) coupling with linear ME voltage coefficient of α ME ~ 0.55 mV/cm·Oe was achieved for x = 0.03 at room temperature. The origin of the ME properties was discussed according to the symmetry evolution. • Optimized α ME of 0.55 mV/cm·Oe is achieved in x = 0.03 samples. • Structure evolution due to Sm substitution dominates enhanced ME effect. • Local polar microdomain is confirmed through polarization dynamics study.