Enhancement of multiferroic properties of Aurivillius Bi5Ti3FeO15 ceramics by Co doping

Multiferroic Bi5Ti3Fe1−xCoxO15 (BFCT-x, where x = 0, 0.1, 0.3, 0.5, 0.7) ceramics were synthesized via a conventional solid-state reaction process and their microstructural, ferroelectric, magnetic and magnetoelectric coupling properties were investigated in detail. All samples show layered perovskite Aurivillius phase with an orthorhombic structure. The highest remanent polarization (2Pr) (35 μC/cm2) has been observed in BFCT-0 ceramic while the BFCT-0.3 ceramic shows the highest remanent magnetization (Mr) (0.13 emu/g) and magnetoelectric coefficient (11.47 mV cm−1 Oe−1). The enhancement of magnetic properties and the magnetoelectric coupling of these ceramics are attributed to the structural distortion caused by Co substitution which subsequently led to ferromagnetic interactions via the Dzyaloshinskii-Moriya interaction.