Magnetoelectric coupling effect in transition metal modified polycrystalline BiFeO₃ thin films

Rare-earth (Sm) and transition metal (Co) modified polycrystalline BiFeO₃ (BFO) thin films have been deposited on Pt/TiO₂/SiO₂/Si substrate successfully through pulsed laser deposition (PLD) technique. Piezoelectric, leakage current and temperature dependent dielectric and magnetic behaviour were investigated for the films. Typical “butterfly-shaped” loop were observed in BSFCO films with an effective piezoelectric constant (d₃₃) ∼94 pm/V at 0.6 MV/cm. High dielectric constant ∼900 and low dielectric loss ∼0.25 were observed at room temperature. M–H loops have shown relatively high saturation magnetization ∼35 emu/cm³ at a maximum field of H ∼20 kOe. Enhanced magnetoelectric coupling response is observed under applied magnetic field. The multiferroic, piezoelectric, leakage current behaviours were explored. Such studies should be helpful in designing multiferroic materials based on BSFCO films. - Highlights: • Transition metal modified polycrystalline BiFeO₃ thin films prepared using PLD. • High ME-coupling response was observed in co-substituted BiFeO₃ thin films. • High magnetization ∼35 emu/cm³ at a maximum field of H ∼20 kOe. • Low leakage current might be due to co-substitution in BiFeO₃ thin films. • A notable piezoelectric constant d₃₃ ∼94 pm/V was found in BiFeO₃ thin films