Ferroelectric, ferromagnetic, and magnetoelectric properties of Bi3.15Nd0.85Ti2.9Zr0.1O12–CoFe2O4 composite films with large magnetoelectric coupling effect

Abstract

The magnetoelectric composite films of Bi3.15Nd0.85Ti2.9Zr0.1O12 (BNTZO)–CoFe2O4 (CFO) were deposited on the substrates of Pt/Ti/SiO2/Si (111) by means of the sol–gel method. The results show that, in the composite films, there are tri-axial compressive stresses in the CFO films. Nevertheless, there are bi-axial tensile stresses and uniaxial compressive stress in the BNTZO films. The composite films possess compact microstructure and flat interface without forming intermediate layer. The composite films have good magnetoelectric properties besides both good ferroelectric and ferromagnetic properties. When Hdc is 738 Oe, the composite film of BNTZO-CFO possesses the maximum of αE, 114 mV cm−1 Oe−1, which is helpful for the application in multi-functional devices.