Improved ferroelectricity and magnetoelectric coupling effect of multielements co‐substituted BiFeO3 ceramics.

In the present work, the strategy of multielements co‐substitution for BiFeO3 ceramics was adopted to enhance the ferroelectricity and magnetoelectric coupling effect where the effective radius of rare‐earth ions was equivalent to that of Sm3+. Differing from the case of Sm‐substituted BiFeO3 ceramics, the symmetry of the present ceramics changed from R3c to Pbnm directly without the formation of Pna21 with increasing RE‐substitution content. The ferroelectricity was significantly improved, and the saturated polarization−electric field (P‐E) hysteresis loop with Pr = 37.63 μC/cm2 was obtained in Bi0.95(La0.20Nd0.20Sm0.20Gd0.20Lu0.20)0.05FeO3 ceramics. The leakage current was reduced by almost six orders of magnitude in multielements co‐substituted BiFeO3 ceramics, which was much lower than that of BiFeO3 end‐member. Moreover, the magnetoelectric coupling coefficient αME of 0.96 mV/cm Oe was achieved in Bi0.86(La0.20Nd0.20Sm0.20Gd0.20Lu0.20)0.14FeO3 ceramics, which was larger than that of Sm‐substituted BiFeO3 ceramics. The strategy of multielements co‐substitution might provide a new approach to improving ferroelectricity and magnetoelectric coupling effect in BiFeO3 ceramics, which could be physically interpreted as the results of the reduced leakage current and increased local polarization configuration caused by the multiple elements substitution. [ABSTRACT FROM AUTHOR]