Giant magnetoelectric torque effect and multicoupling in two phases ferromagnetic/piezoelectric system

The physical mechanism of a non-magnetostrictive magnetoelectric (ME) effect was revealed and designated as the ME torque (MET) effect. Experimental results showed that the MET effect could be huge; a simple MET device could achieve giant ME voltage coefficients of 100 V/cm. Oe at 1Hz and 2100 V/cm. Oe at the first order resonant frequency. These are the highest reported ME coefficients in a bulk device ever. We then proposed the multicoupling ME effect, which comes from the interaction of magnetostriction, magnetic torque, and piezoelectricity, and rewrite the ME constitutive tensor equation. The abnormal phenomenon in the (1-3) structure ME thin film that T-L mode might bring larger ME coupling than L-L mode was successfully explained from the multicoupling concept. These researches have extended the giant ME effect from the traditional magnetostrictive/piezoelectric system to a common ferromagnetic/piezoelectric system, and gave more choices to scientists/engineers for constructing the giant ME device. (C) 2011 American Institute of Physics. [doi:10.1063/1.3662912]