****NON-TECHNICAL ABSTRACT***** Materials that are capable of magnetic field-to-electric field conversion are potentially useful for a variety of technologies. There are few such magneto-electric materials in nature and most of them have a low efficiency when converting fields. This research is aimed at artificial composite materials with excellent conversion properties. The composites will be made by bonding plates of ferrites, which deform in a magnetic field, together with ferroelectrics, which produce an electric field when deformed. The field conversion properties will be studied over a wide frequency range for information on their use in consumer electronics, communication devices, and radar systems. These projects will provide research training for personnel at all levels, from high school sophomores to post doctoral associates.
A comprehensive research program is planned on wide-band magnetoelectric (ME) interactions in bilayers of single crystal ferrites and ferroelectrics. The electromagnetic coupling in such systems is mediated by mechanical stress: magnetostriction induced mechanical deformation and the piezoelectric effect induced electric fields. Theories predict orders of magnitude stronger ME interactions in single crystals compared to polycrystalline multilayers. The primary tasks and goals are as follows. (i) The fabrication of bilayers consisting of spinel ferrites and piezoelectrics by bonding techniques. (ii) Measurement and analysis of ME dispersion characteristics, including Maxwell-Wagner relaxation, and low-frequency ME effects. (iii) Investigations on resonant ME effect when the electric and magnetic subsystems show resonance behavior. Human resource development will involve personnel at all levels, from high school students to research associates. The ME materials are potential candidates for magnetoelectric memory devices, magnetic field sensors, electrically controlled magnetic devices, and magnetically controlled piezoelectric devices.
