Magnetoelectric Properties of CoFe{sub}2O{sub}4-BaTiO{sub}3 Core-Shell Structure Composites

摘要

Magnetoelectric (ME) materials become magnetized when placed in an electric field and electrically polarized when placed in a magnetic field. Thus an effective conversion between electric and magnetic energy becomes possible, and ME materials present themselves as one kind of smart materials. They can be classified into two classes: single phase and composite. For single phase materials, due to the primary requirement to observe the ME effect is the coexistence of magnetic and electric dipoles in an asymmetric structure, the number of compounds that exhibit ME effect is limited, the ME coefficient, α{sub}E=({partial deriv}E/{partial deriv}H){sub}T, is small, working temperature is low and involved expensive materials and processing techniques. These limitations can be overcome when shifted to composites, which usually consist of magnetostrictive and piezoelectric phases, resulting in a ME effect as product property of this combination [1].