Magnetoelectric Interaction Phenomena In Crystals

In the quest for higher data density in information technology manipulation of magnetization by other means than magnetic fields has become an important challenge. This lead to a startling revival of the magnetoelectric effect, which characterizes induction of a polarization by a magnetic field or of a magnetization by an electric field. The magnetoelectric crosslink of material properties opens just those degrees of freedom which are needed for the mutual control of magnetic and electric states. The book gives a state-of-the-art review on magnetoelectrics research, classifies current research tendencies, and points out possible future trends. Novel compounds and growth techniques and new theoretical concepts for the understanding of magnetoelectric coupling phenomena are introduced. Highlights are the discovery of "gigantic" magnetoelectric effects which are strong enough to trigger electric or magnetic phase transitions; the concept of magnetochirality; and development "structural" magnetoelectric effects in artificial multiphase compounds. The book is addressed to condensed-matter physicists with a particular focus on experts in highly correlated systems.

Complex-mediums electromagnetics (CME) describes the study of electromagnetic fields in materials with complicated response properties. This truly multidisciplinary field commands the attentions of scientists from physics and optics to electrical and electronic engineering, from chemistry to materials science, to applied mathematics, biophysics, and nanotechnology. This book is a collection of essays to explain complex mediums for optical and electromagnetic applications. All contributors were requested to write with two aims: first, to educate; second, to provide a state-of-the-art review of a particular subtopic. The vast scope of CME exemplified by the actual materials covered in the essays should provide a plethora of opportunities to the novice and the initiated alike.

This book brings together numerous contributions to the field of magnetoelectric (ME) composites that have been reported since the beginning of the new millennium. It presents 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. This book discusses 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.

The inspiration for this book can be traced back many years to two major works that in?uenced the author’s outlook on applied physics: FerromagnetismusbyR. Becker,W. D ̈ oring (Springer, Berlin 1939), and Ferromagnetism by R. M. Bozorth (IEEE Press, New York 1951). The former work is a collection of lectures held in the 1930s for ‘technicians’ attending a technical college. The German language in which the work was originally written was extremely convenient for the author of this present book, as it was for a long time the only comfortable technical language in an English speaking environment. Later on, upon encountering the work by Bozorth, it was a relief to see the clarity and eloquence of the subjects presented in English, despite the impressive thickness of the book. Bozorth’s work still constitutes a practical review for anyone in a multidisciplinary industry who comes across the various manifestations of magnetism. The popularity of both works is so enduring that they are regarded as highly academic, and yet extremely readable, a reference in their own right, still attracting many readers these days in industry and academia. The ?eld of magnetism progressed immensely in the twentieth century, and shows no signs of slowing down in the present one. It has become so vast that it is quite often viewed only in its parts, rather than as a whole. In today’smyriadofapplications,especiallyonananoscale,andtheirchangeable implications mostly on a macroscale, it often seems that di?erent aspects of reported work on magnetism are scattered and unrelated.

This book is dedicated to modeling and application of magnetoelectric (ME) effects in layered and bulk composites based on magnetostrictive and piezoelectric materials. Currently, numerous theoretical and experimental studies on ME composites are available but few on the development and research of instruments based on them. So far, only investigation of ME magnetic field sensors has been cited in the existing literature. However, these studies have finally resulted in the creation of low-frequency ME magnetic field sensors with parameters substantially exceeding the characteristics of Hall sensors. The book presents the authors’ many years of experience gained in ME composites and through creation of device models based on their studies. It describes low-frequency ME devices, such as current and position sensors and energy harvesters, and microwave ME devices, such as antennas, attenuators, filters, gyrators, and phase shifters.

Although several books and conference proceedings have already appeared dealing with either the mathematical aspects or applications of homogenization theory, there seems to be no comprehensive volume dealing with both aspects. The present volume is meant to fill this gap, at least partially, and deals with recent developments in nonlinear homogenization emphasizing applications of current interest. It contains thirteen key lectures presented at the NATO Advanced Workshop on Nonlinear Homogenization and Its Applications to Composites, Polycrystals and Smart Materials. The list of thirty one contributed papers is also appended. The key lectures cover both fundamental, mathematical aspects of homogenization, including nonconvex and stochastic problems, as well as several applications in micromechanics, thin films, smart materials, and structural and topology optimization. One lecture deals with a topic important for nanomaterials: the passage from discrete to continuum problems by using nonlinear homogenization methods. Some papers reveal the role of parameterized or Young measures in description of microstructures and in optimal design. Other papers deal with recently developed methods – both analytical and computational – for estimating the effective behavior and field fluctuations in composites and polycrystals with nonlinear constitutive behavior. All in all, the volume offers a cross-section of current activity in nonlinear homogenization including a broad range of physical and engineering applications. The careful reader will be able to identify challenging open problems in this still evolving field. For instance, there is the need to improve bounding techniques for nonconvex problems, as well as for solving geometrically nonlinear optimum shape-design problems, using relaxation and homogenization methods.

This book brings together numerous contributions to the field of magnetoelectric (ME) composites that have been reported so far. Theoretical models of ME coupling in composites relate to the wide frequency range: from low-frequency to microwave ones and are based on simultaneous solving the elastostatic/elastodynamic and electrodynamics equations. Suggested models enable one to optimize magnetoelectric parameters of a composite. The authors hope to provide some assimilation of facts into establish knowledge for readers new to the field, so that the potential of the field can be made transparent to new generations of talent to advance the subject matter.

Composite Magnetoelectrics: Materials, Structures, and Applications gives the reader a summary of the theory behind magnetoelectric phenomena, later introducing magnetoelectric materials and structures and the techniques used to fabricate and characterize them. Part two of the book looks at magnetoelectric devices. Applications include magnetic and current sensors, transducers for energy harvesting, microwave and millimeter wave devices, miniature antennas and medical imaging. The final chapter discusses progress towards magnetoelectric memory. Summarises clearly the theory behind magnetoelectric phenomena Strong coverage of fabrication and characterisation techniques Reviews a broad range of current and potential magnetoelectric devices