Dynamic Measurements of Magnetoelectricity in Metglas-Piezocrystal Laminates

This chapter describes an experimental technique, developed experimental setup and respective experimental study of the dynamic properties of direct magnetolelectric (ME) effect measured in metglas-piezocrystal laminates. We have prepared a variety of different magnetoelectric laminates by bonding magnetostrictive metglas foils onto single-crystalline substrates of LiNbO₃ (LNO), GaPO₄ (GPO) and PMN-PT. The measurements have been performed as a function of the crystal cut, magnitude and orientation of the magnetic bias field and the frequency of the modulation field. Despite much weaker PE coefficients of LNO and GPO, direct ME effects have been found to have comparative magnitudes in the samples based on them and on PMN-PT. Greatly enhanced ME coefficients in certain resonance modes are explored and their relations to the material properties of the crystals and the geometry of the composites are investigated. We demonstrate that control of the PE crystal’s orientation can be successfully used in order to obtain almost any desired quasi-static and resonant anisotropic ME properties for some given application. Such unique features as chemical stability, linear piezoelectricity, thermal robustness open up a real perspective to use lead-free LNO and α-GPO based ME tri-layers, e.g., as vector magnetic field sensors working in a wide range of temperatures.