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

In the present work, the strategy of multielements co-substitution for BiFeO 3 ceramics was adopted to enhance the ferroelectricity and magnetoelectric coupling effect where the effective radius of rare-earth ions was equivalent to that of Sm 3+ . Differing from the case of Sm-substituted BiFeO 3 ceramics, the symmetry of the present ceramics changed from R3c to Pbnm directly without the formation of Pna 2 1 with increasing RE-substitution content. The ferroelectricity was significantly improved, and the saturated polarization−electric field ( P - E ) hysteresis loop with P r = 37.63 μC/cm 2 was obtained in Bi 0.95 (La 0.20 Nd 0.20 Sm 0.20 Gd 0.20 Lu 0.20 ) 0.05 FeO 3 ceramics. The leakage current was reduced by almost six orders of magnitude in multielements co-substituted BiFeO 3 ceramics, which was much lower than that of BiFeO 3 end-member. Moreover, the magnetoelectric coupling coefficient α ME of 0.96 mV/cm Oe was achieved in Bi 0.86 (La 0.20 Nd 0.20 Sm 0.20 Gd 0.20 Lu 0.20 ) 0.14 FeO 3 ceramics, which was larger than that of Sm-substituted BiFeO 3 ceramics. The strategy of multielements co-substitution might provide a new approach to improving ferroelectricity and magnetoelectric coupling effect in BiFeO 3 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.