Magnetoelectric composite thin films containing multiferroic Bi4Ti3-xNixO12 single-phase and ferromagnetic La0.67Sr0.33MnO3 components

Magnetoelectric (ME) composite thin films , composed of Ni-doped Bi 4 Ti 3 O 12 (Bi 4 Ti 3-x Ni x O 12 , x = 0.025, 0.05, 0.10 and 0.15) and ferromagnetic La 0.67 Sr 0.33 MnO 3 (LSMO), were fabricated on LaNiO 3 -buffered Si substrates using the chemical solution deposition technique. A comprehensive investigation wasconducted to explore the influence of the Ni doping content on multiple properties of the thin films, including their microstructure, ferromagnetism , leakage conduction characteristics, dielectric properties , ferroelectric behavior, and ME coupling performance. Notably, Ni-doping induces the successful transformation of Bi 4 Ti 3 O 12 from a pure ferroelectric phase to a multiferroic component, and a ME coupling voltage coefficient ( α E ) value of 0.48 mV/cm·Oe is achieved in the Bi 4 Ti 2.95 Ni 0.05 O 12 (BiTiN 0.05 O) single-phase thin film. Furthermore, as the Ni doping content increases, properties such as leakage conduction, dielectric properties, and ferroelectricity exhibit a trend of first improving and subsequently deteriorating. Among them, the BiTiN 0.05 O/LSMO composite thin film demonstrates optimal comprehensive dielectric and ferroelectric properties, with a remnant polarization of 23.7 μC/cm 2 and a coercive field of 107 kV/cm. Significantly, the BiTiN 0.05 O/LSMO composite thin film shows an outstanding α E of 330.2 mV/cm·Oe, which is higher than that of many reported ferromagnetic-ferroelectric composite thin films.