Enhanced Curie temperature and magnetoelectric effects in the BaTiO3-based piezoelectrics and CoFe2O4 laminate composites

In the present work, the 0.65BaTiO3-0.35Bi0.5Na0.5TiO3/CoFe2O4 laminate composites targeting lead-free magnetic field sensor, which can be used at high operating temperatures without depolarizing, were prepared by the conventional solid-state sintering method. Excellent dielectric, piezoelectric, magnetic and magnetoelectric properties can be observed in the 0.65BaTiO3-0.35Bi0.5Na0.5TiO3/CoFe2O4 laminate composites compared with the BaTiO3/CoFe2O4 laminate composites. The ME response is dependent on the relative mass ratio of 0.65BaTiO3-0.35Bi0.5Na0.5TiO3 phase and CoFe2O4 phase and the dc magnetic field. The maximum ME coefficient of the 0.65BaTiO3-0.35Bi0.5Na0.5TiO3/CoFe2O4 laminate composites reaches up to about 113 mV/cm Oe, which is larger than that of the BaTiO3/CoFe2O4 laminate composites (86 mV/cm Oe).