Multiferroic,magnetoelectric and magneto-impedance properties of NiFe2O4/(Pb,Sr) TiO3 bilayer films

We prepared NiFe₂O₄/(Pb, Sr)TiO₃ (NFO/PST) bilayer films by the chemical solution method and investigated their multiferroic, magnetoelectric and magneto-impedance properties. Multiferroic properties have been observed at room temperature. The bilayer films exhibit saturation polarization P _s ? 26.6 μC/cm² and saturation magnetization M _s ? 134 emu/cm³. With increasing Sr content, M _s. and P _s values of the NFO/PST bilayer films decrease. The variation may be ascribed to the influence of interfacial strain and decrease in tetragonality. High magnetoelectric coupling effect has been observed in the NFO/PST bilayer films with maximum value of α _E  = 6.35 Vcm^?1 Oe^?1 measured at H _DC  ~ 1 kOe and f ~ 10 kHz for Sr ~ 10% (NFO/PST10). The magneto-impedance measurements establish a strong dependence on magnetic field, further confirming magnetoelectric response in NFO/PST bilayer films. An alternative approach for impedance analysis of NFO/PST10 bilayer film provides direct evidence of strain mediated magnetoelectric coupling at room temperature. The results indicate that NFO/PST bilayer films can be considered as a potential multiferroic magnetoelectric material.