Dielectric and tunable ferroelectric properties in BiFeO3–BiCoO3–BaTiO3 ternary compound

The ternary compound BiFeO3–BiCoO3–BaTiO3 (BFO–BCO–BT) was prepared using the solid-state reaction method. The dielectric studies display strong frequency-dependent anomaly in the vicinity of Curie temperature (TC) ≈ 350 °K and exhibit strong diffusive relaxor behavior with (γ ≈ 1.61). The dielectric measurements confirm stabilization in BFO–BT solid solution due to BCO addition. The P–E loops display strong ferroelectric behavior and frequency variation indicating major dominant domain wall movement on high dielectric constant in the BFO–BCO–BT ternary compound. The magnetic field variation in the P–E loop displays strong magnetoelectric coupling originating from interfacial polarization with maximum coupling coefficient of 115 mV/cm-Oe at field of 500 Oe. The temperature variation of P–E shows enhanced configurational entropy due to increase in activation energy, with the highest isothermal energy (ΔS) = 0.15 J/kg/K obtained for E = 15 kV/cm and T = 125 °C. These studies provide tunable ferroelectric properties of BFO–BCO–BT for exploration of promising applications such as refrigeration and magnetoelectricity.