Room temperature magnetoelectric coupling in Fe-doped sodium bismuth titanate ceramics

Multiferroic ceramics with switchable magnetization as well as high polarization at room temperature have remarkable technological impact. Herein, we report that a small concentration of Fe doping in the B-site of sodium bismuth titanate (NBT) lead to room temperature multiferroic nature with fascinating properties. The key factor responsible for the embellished multiferroic behavior at room temperature was electric field induced non-180° domain alignment bridged with dynamic exchange interaction of trapped electrons in ordered polarons. The optimum doping of 0.02 mole fractions Fe in NBT favored ferromagnetic loop with highest remanence of 198 memu/g and coercive field 133 Oe along with improved ferroelectric polarization of 31.8 μC/cm2 and a strong self-biased direct magnetoelectric coupling coefficient of 7.38 mV/cmOe. Strong coupling at low ac field, high reliability, easy control by an electric signal and fast switching behavior add importance to this lead-free Fe-doped sodium bismuth titanate ceramic as potential material, applicable in biocompatible magnetic sensors. •Fe doped sodium bismuth titanate ceramics were synthesized by solid state reaction.•Improved ferroelectric and ferromagnetic nature was obtained.•A reinforced self-biased magnetoelectric coupling of 7.38 mV/cmOe was observed.•Electric field induced non-180° domain alignment led to enhanced multiferroic behavior.