Magnetoelectric (ME) composites, which simultaneously exhibit ferroelectricity and ferromagnetism, have recently stimulated a sharply increasing number of research activities for their scientific interest and significant technological promise in the novel multifunctional devices. Natural single-phase compounds are rare, and their magnetoelectric responses are either relatively weak or occur at temperatures too low for practical applications. In contrast, composites that incorporate both ferroelectric and ferri-/ferromagnetic phases typically yield giant magnetoelectric coupling response above room temperature, which makes them ready for technological applications. In such composites, the magnetoelectric effect is generated as a product property of a magnetostrictive and a piezoelectric substance. Appropriate choice of phases with high magnetostriction and piezoelectricity has allowed the achievement of ME voltage coefficients necessary for engineering applications over a wide frequency bandwidth including the electromechanical, magnetoacoustic, and ferromagnetic resonances regimes.
The authors of this book have attempted to bring together numerous contributions to the field of ME composites that have been reported since the beginning of the new millennium. They present to the readers new to the field some assimilation of facts into the established knowledge, so that the potential of the field can be made transparent to the new generations of talent to advance the subject matter.
Interestingly, motivated by on-chip integration in microelectronic devices, nanostructured composites of ferroelectric and magnetic oxides have recently been deposited in a film-on substrate geometry. The coupling interaction between nanosized ferroelectric and magnetic oxides is also responsible for the magnetoelectric effect in nanostructures, as was the case in those bulk composites. The availability of high-quality nanostructured composites makes it easier to tailor their properties through epitaxial strain, atomic-level engineering of chemistry, and interfacial coupling. In this book, the authors discuss these bulk and nanostructured magnetoelectric composites from both experimental and theoretical perspectives. From application viewpoint, microwave devices, sensors, transducers, and heterogeneous read/write devices are among the suggested technical implementations of magnetoelectric composites.
