Ferroelectric, Dielectric, Ferromagnetic, and Magnetoelectric Properties of BNF-NZF Bilayer Nanofilms Prepared via Sol-Gel Process

Bilayer magnetoelectric (ME) nanofilms composed of Bi(0.9)Nd(0.1)FeO(3) (BNF) and Ni(0.55)Zn(0.45)Fe(2)O(4) (NZF) were fabricated on the Pt(111)/Ti/SiO(2)/Si(100) substrates via sol-gel and a subsequent rapid thermal process with different growth sequences of BNF and NZF forming the following layered structures: BNF/NZF and NZF/BNF. The phase composition, microstructure, and ferroelectric, dielectric, ferromagnetic, and ME coupling properties of the composites were investigated at room temperature. Structural characterization by X-ray diffraction and scanning electron microscopy showed that there are no other impurity phases but BNF and NZF, and the nucleation barrier caused that it is easier for NZF and BNF to grow on each other rather than on the surface of Pt/Ti/SiO(2)/Si. The tests of the physical properties indicated that such heterostructures present both good ferroelectric, ferromagnetic, and dielectric properties and the in-plane ME coupling coefficient α(E) at room temperature but some discrepancies also exist, which can be attributed to an interfacial effect, in other words, the deposition sequences of the constituent phases have a great influence on the properties of bilayer films.