Impact of heat-treatment conditions on ferroelectric, ferromagnetic and magnetoelectric properties of multi-layered composite films of Ba0.9Ca0.1TiO3/CoFe2O4

The magnetoelectric films of Ba 0.9 Ca 0.1 TiO 3 (BCT)/CoFe 2 O 4 (CFO) were deposited on Pt(111)/Ti/SiO 2 /Si(100) substrates by the sol-gel and spin-coating method under three kinds of heat-treatment conditions. It is shown that the heat-treatment conditions have a great effect on the ferroelectric, ferromagnetic and magnetoelectric properties of the composite films. Among the composite films prepared under three kinds of heat-treatment conditions, the composite films prepared under the complete heat-treatment condition (CHC composite films) have the best ferroelectric, ferromagnetic and magnetoelectric properties. They possess largest value of α E (82 mV cm −1 Oe −1 ). The complete heat-treatment condition is the most appropriate heat-treatment condition for obtaining the best magnetoelectric properties. Ferroelectric phase and ferromagnetic phase can coexist without inter-diffusion at the interface in CHC composite films.