Elastically coupled magneto-electric elements with highly magnetostrictive amorphous films and PZT substrates

Elastically coupled magneto-electric (ME) elements were constructed and their fundamental properties were studied, so as to examine whether the elements exhibit considerable ME effect at room temperature. The elements had a hybrid structure, in which thin soft grass substrates with highly magnetostrictive amorphous FeCoSiB films were bonded on lead zirconate titanate (PZT) piezoelectric substrates. When a direct current (dc) voltage was applied to the element large changes in the magnetic properties of the FeCoSiB film were observed. For example, by applying a de voltage from -200 V to +200 V, changes in magnetic permeability of the film reached about 1680%. It was also demonstrated that high-frequency impedance of the element was subject to change with a de voltage applied to PZT layer. These unique characteristics of the present ME elements are considered to be very attractive for constructing smart actuators with a sensing function.