This book deals with many aspects of high density digital recording. It begins with very basic concepts in magnetism and magneto-optics, then continues with the synthesis and physical properties of recording media, thin films and particulate media. More technological aspects of recording heads and their contact with the recording media are also discussed in subsequent chapters. The second part of the book is devoted to the magneto-optical properties of various recording media and to the engineering of magneto-optical recording.

In this book, the fundamentals of magnetism are treated, starting at an introductory level. The origin of magnetic moments, the response to an applied magnetic field, and the various interactions giving rise to different types of magnetic ordering in solids are presented and many examples are given. Crystalline-electric-field effects are treated at a level that is sufficient to provide the basic knowledge necessary in understanding the properties of materials in which these effects play a role. Itinerant-electron magnetism is presented on a similar basis. Particular attention has been given to magnetocrystalline magnetic anisotropy and the magnetocaloric effect. Also, the usual techniques for magnetic measurements are presented. About half of the book is devoted to magnetic materials and the properties that make them suitable for numerous applications. The state of the art is presented of permanent magnets, high-density recording materials, soft-magnetic materials, Invar alloys and magnetostrictive materials. Many references are given.

Over the last few decades magnetism has seen an enormous expansion into a variety of different areas of research, notably the magnetism of several classes of novel materials that share with truly ferromagnetic materials only the presence of magnetic moments.

Volume 21 of the "Handbook of Magnetic Materials," like the preceding volumes, has a dual purpose.With contributions from leading authorities in the field, it includesa variety oftopicswhich are intendedas self-containedintroductions toa givenarea in the field of magnetism without requiring recourse to the published literature. It is also intended as a reference for scientists active in magnetism research, providing readers with novel trends and achievements in magnetism.Volume 21 comprises topical review articles covering Heusler compounds, quasicrystalline solids, bulk amorphous alloys and nanocrystalline soft-magnetic alloys. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material within the framework of physics, chemistry and material science.
Composed of topical review articles written by leading authoritiesIntroduces given topics in the field of magnetismProvides the reader with novel trends and achievements in magnetism"

Volume 19 of the "Handbook of Magnetic Materials," as the preceding volumes, has a dual purpose. As a textbook it is intended to help those who wish to be introduced to a given topic in the field of magnetism without the need to read the vast amount of literature published. As a work of reference it is intended for scientists active in magnetism research. To this dual purpose, Volume 19 is composed of topical review articles written by leading authorities. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material in the framework of physics, chemistry and material science. It provides readers with novel trends and achievements in magnetism.
Composed of topical review articles written by leading authoritiesIntended to be of assistance to those who wish to be introduced to a given topic in the field of magnetismAs a work of reference it is intended for scientists active in magnetism researchProvide the readership with novel trends and achievements in magnetism

Volume20 of the "Handbook of Magnetic Materials," as the preceding volumes, has a dual purpose. As a textbook it is intended to help those who wish to be introduced to a given topic in the field of magnetism without the need to read the vast amount of literature published. As a work of reference it is intended for scientists active in magnetism research. To this dual purpose, Volume20 is composed of topical review articles written by leading authorities. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material in the framework of physics, chemistry and material science. It provides readers with novel trends and achievements in magnetism.
Composed of topical review articles written by leading authoritiesIntended to be of assistance to those who wish to be introduced to a given topic in the field of magnetismAs a work of reference it is intended for scientists active in magnetism researchProvide the readership with novel trends and achievements in magnetism "

Volume 10 of the Handbook is composed of topical review articles written by leading authorities. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material in the framework of physics, chemistry and materials science.

Of all the new superconducting materials investigated having a more than three times highter transition temperature, the cuprates are the most prominent. Although originally intended as novel superconducting compounds, these materials have opened a new field of magnetism that permits detailed studies of the propagation of magnetic order as a function of separation and crystallographic orientation as well as studies of the interplay of strain and magnetic properties. Chapter one presents a detailed account of acheivements in this field.

Further chapters report on the progress being made in research areas that have been dealt with in previous volumes of the Handbook. These include the group of soft magnetic materials in which supplementary results dealing with nanocrystalline alloys are highlighted; the magnetic properties of intermetallic compounds in which rare earth elements are combined with nonmagnetic elements; progress in the development in hard magnetic materials, with the emphasis on novel developments in the manufacturing routes and the physical principles on which these new developments are based.

Volume 15 of the Handbook on the Properties of Magnetic Materials, as the preceding volumes, has a dual purpose. As a textbook it is intended to be of assistance to those who wish to be introduced to a given topic in the field of magnetism without the need to read the vast amount of literature published. As a work of reference it is intended for scientists active in magnetism research. To this dual purpose, Volume 15 of the Handbook is composed of topical review articles written by leading authorities. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material in the framework of physics, chemistry and material science. It provides the readership with novel trends and achievements in magnetism.

Since the publication of volume 3 in 1982 there has been a revival of research on magnetism and a pronounced increase in interest from both the scientific and the technological side. Volume 5 therefore contains chapters that provide the reader with an insight into modern trends in magnetism and new achievements in this area. The topics dealt with here include the increased activity and investigations of the magnetism of magnetic superconductors and investigations of the magnetic properties of hydrides, the understanding of first-order magnetic processes and of quadrupolar interactions in 4f systems and their role in magnetic ordering and magneto-elastic effects, and the magnetism of strongly enhanced itinerant alloys and compounds and the magnetism of Invar alloys.

Volume 11 of this prestigious series, as the preceding volumes, has a dual purpose. As a textbook it is intended to be of assistance to those who wish to be introduced to a given topic in the field of magnetism without the need to read the vast amount of literature published. As a work of reference it is intended for scientists active in magnetism research. In keeping with this dual purpose, Volume 11 of the Handbook is composed of topical review articles written by leading authorities. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material in the framework of physics, chemistry and materials science.

Chapter one focuses on the growing interest in intermetallic compounds based on uranium. Recent research activities have finally led to the crystallisation of new concepts in actinide magnetism which, together with the large amount of experimental work are reviewed in this chapter.

The last few decades have witnessed quite an extraordinary development in magnetic recording technology. In the near future magnetic recording technology will have an enormous growth potential, one of it's main aims being the further reduction in the peripheral device sizes while maintaining an increase in capacity. Chapter two deals with the magnetism and materials aspects of hard disk media which are the most prominent type of mass storage today, due to their low cost, high speed and relatively high storage capacity.

Magnets based on rare earth elements are unequalled with regard to coercivity and maximum energy production. Considerable progress has been made in the development of rare earth based permanent magnets which goes hand in hand with a better understanding of the physical properties and especially the magnetism of the underlying class of materials. Chapter three presents a survey of the physical principles involved with this technique and how these can be applied advantageously to the study of strongly ferromagnetic materials.

The final chapter is devoted to inelastic neutron scattering when applied to study the crystal field interaction in lanthanide compounds. Included in this review is a description of how this technique is complementary to various other modern and conventional techniques.

This volume is composed of topical review articles written by leading authorities in the field. As in previous volumes in the series, each article presents an extensive description in graphical as well as in tabular form, placing emphasis on the discussion of the experimental material in the framework of physics, chemistry and material science.
Chapter one focuses on GMR in magnetic multilayers, spin valves, multilayers on grooved substrates and multilayered nanowires. Furthermore it comprises theoretical models and employs the experimental data to discuss the current understanding of GMR and the underlying physics.
A key aspect of the study of the properties of thin magnetic films and multilayers is the relationship between the structural and magnetic properties of the material, which has become one of the most active areas of research in magnetism in recent years. NMR is a well-known technique that offers the possibility to obtain experimental information on atomic scale properties in systems with reduced dimensionality. Chapter two reviews the results obtained by NMR on the latter systems. Written in tutorial style it will be helpful to scientists familiar with the preparation and properties of thin magnetic films but having little knowledge of the NMR of ferromagnetic materials.
Chapter three examines rare-earth compounds with 3d transition metals, in particular those that exhibit a magnetic instability of the 3d-subsystem. It focuses on such compounds in which the d-electron subsystem is neither non-magnetic, nor carries a stable magnetic moment.
The last chapter is concerned with the promising technology of magnetic refrigeration which can be used in a broad range ofapplications. It is based on the magnetocaloric effect associated with the entropy change occurring when a magnetic material is isothermally subjected to a changing magnetic field and the temperature change when the field is changed adiabatically. The last decade has witnessed quite a strong development in magnetic cooling technology and research activities in this field have been extended to a variety of magnetocaloric materials, including amorphous alloys, nanocomposites, intermetallic compounds and perovskite type oxides. The many materials, their magnetocaloric efficiency as well as the physical principles behind it are reviewed in this final chapter.

Magnetoelectronics is a novel and rapidly developing field. This new field is frequently referred to as spin-electronics or spintronics. It includes spin-utilizing devices that need neither a magnetic field nor magnetic materials. In semiconductor devices, the spin of the carriers has only played a very modest role so far because well established semiconductor devices are non-magnetic and show only negligible effects of spin. Nanoscale thin films and multilayers, nanocrystalline magnetic materials, granular films, and amorphous alloys have attracted much attention in the last few decades, in the field of basic research as well as in the broader field of materials science. Such heterogeneous materials display uncommon magnetic properties that virtually do no occur in bulk materials. This is true, in particular with respect to surface (interface) magnetic anisotropy and surface (interface) magnetostrictive strains and giant magnetoresistance. The local atomic arrangement at the interface differs strongly from that in the bulk. The local symmetry is lowered, so that some interactions are changed or are missing altogether.
The interface atoms may envisaged as forming a new phase and some properties characteristic of this phase may become predominant for the entire system.
This becomes particularly evident in the case of interfacial magnetostriction which can lead to a decrease (almost to zero) or to an increase(over the bulk value) of the resulting magnetostriction of the nanoscale system.
There are various forms of the interplay of magnetism and superconductivity, which can be divided into competition and coexistence phenomena. For instance, a strong competition is found in high-Tc cuprates. In these materials, depending on the doping rate, either Neel-type antiferromagnetism moments (e.g. from 4f-elements) with superconductivity is known to occur in systems where the concentration of these moments is sufficiently small or where they are antiferromagnetically ordered and only weakly coupled to the conduction electrons.
During the years, intermetallic gadolinium compounds have adopted a special position in the study of 4f electron magnetism. The reason for this is the fact that the gadolinium moment consists only of a pure spin moment, orbital contributions to the moment being absent. As a consequence, gadolinium compounds have been regarded as ideal test benches for studying exchange interactions, free from complications due to crystal effects.
Volume 14 of the Handbook of Magnetic Materials, as the preceding volumes, has a dual purpose. As a textbook it is intended to be of assistance to those who wish to be introduced to a given topic in the field of magnetism without the need to read the vast amount of literature published. As a work of reference it is intended for scientists active in magnetism research. To this dual purpose, volume 14 of the Handbook is composed of topical review articles written by leading authorities. In each of these articles an extensive description is given in graphical as well as tabular form, much emphasis being placed on the discussion of the experimental material in the framework of physics, chemistry and material science.

Volume 7 of the Handbook of Magnetic Materials provides an overview of some of the most exciting topics in magnetism today.

Firstly, a substantial step forward in the understanding of metallic magnetism has been reached by means of electronic band structure calculation. Progress in this area has been made not only due to the availability of high speed computing machines but also due to sophistication in the computational methodology. Two chapters are devoted to this subject, one of which is devoted to the elements and the other dealing primarily with 4f and 5f systems, including examples of the large group of intermetallic compounds. In both chapters the authors have concentrated on explaining the physics behind these band calculations. The chapters are written in a manner understandable to scientists having no experience with band calculations.

Thin film technology has become a key issue in high density magnetic and magneto-optical recording and will be dealt with in future volumes of the Handbook. The present volume introduces the field with a chapter on the magnetism of ultrathin transition metal films, describing the richness in novel magnetic phenomens that has been encountered in the past few years in these materials. Of equal interest are the novel magnetic phenomena observed when magnetic moments are incorporated in a semiconducting matrix. A comprehensive description of these materials is found in the chapter on diluted magnetic semiconductors. A separate chapter is devoted to the progress made in the field of heavy fermions and valence fluctuations, emphasis being placed on the important results obtained by means of neutron scattering. A detailed review of the progress made in the field of rare earth based intermetallic compounds in combination with 3d transition metals completes this multifaceted volume.

Volume 9 of the "Handbook of Magnetic Materials" has a dual purpose, as do the preceding volumes in the series. As a textbook it is intended to be of assistance to those who wish to be introduced to a given topic in the field of magnetism without the need to read the vast amount of literature published. As a work of reference it is intended for scientists active in magnetism research. To this dual purpose, Volume 9 of the Handbook is composed of topical review articles written by leading authorities. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material in the framework of physics, chemistry and material science.

Chapter one presents a general account of the magnetism of heavy-fermion systems. Two novel experimental techniques are described in chapters two and five. Chapter two deals with muon spin rotation and chapter five gives an account of the possibilities offered by photon beam spectroscopy. In both chapters it is shown how these sophisticated experimental methods can be used to obtain experimental information not easily obtainable by conventional experimental methods. Chapter three deals with interstitially modified intermetallic compounds of rare earth and 3d elements. Finally chapter four is concerned with thermodynamic approach to phase transitions and shows how the understanding and description of these magnetic phase transitions can be considerably enriched.

Volume 17 of the Handbook on the Properties of Magnetic Materials, as the preceding volumes, has a dual purpose. As a textbook it is intended to be of assistance to those who wish to be introduced to a given topic in the field of magnetism without the need to read the vast amount of literature published. As a work of reference it is intended for scientists active in magnetism research. To this dual purpose, Volume 17 of the Handbook is composed of topical review articles written by leading authorities. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material in the framework of physics, chemistry and material science. It provides the readership with novel trends and achievements in magnetism.
*composed of topical review articles written by leading authorities
*intended to be of assistance to those who wish to be introduced to a given topic in the field of magnetism
*as a work of reference it is intended for scientists active in magnetism research
*provide the readership with novel trends and achievements in magnetism

Volume 18 of the "Handbook of Magnetic Materials," as the preceding volumes, has a dual purpose. As a textbook it is intended to help those who wish to be introduced to a given topic in the field of magnetism without the need to read the vast amount of literature published. As a work of reference it is intended for scientists active in magnetism research. To this dual purpose, Volume 18 is composed of topical review articles written by leading authorities. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material in the framework of physics, chemistry and material science. It provides readers with novel trends and achievements in magnetism.
Composed of topical review articles written by leading authoritiesIntended to be of assistance to those who wish to be introduced to a given topic in the field of magnetismAs a work of reference it is intended for scientists active in magnetism researchProvide the readership with novel trends and achievements in magnetism

Volume 16 of the Handbook on the Properties of Magnetic Materials, as the preceding volumes, has a dual purpose. As a textbook it is intended to be of assistance to those who wish to be introduced to a given topic in the field of magnetism without the need to read the vast amount of literature published. As a work of reference it is intended for scientists active in magnetism research. To this dual purpose, Volume 16 of the Handbook is composed of topical review articles written by leading authorities. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material in the framework of physics, chemistry and material science. It provides the readership with novel trends and achievements in magnetism.
* composed of topical review articles written by leading authorities.
* intended to be of assistance to those who wish to be introduced to a given topic in the field of magnetism.
* as a work of reference it is intended for scientists active in magnetism research.
* provides the readership with novel trends and achievements in magnetism.

Over the last few decades, magnetism has seen an enormous expansion into a variety of different areas of research, notably the magnetism of several classes of novel materials that share with truly ferromagnetic materials only the presence of magnetic moments.

Volume 22 of the "Handbook of Magnetic Materials," like the preceding volumes, has a dual purpose. With contributions from leading authorities in the field, it includes a variety of topics which are intended as self-contained introductions to a given area in the field of magnetism without requiring recourse to the published literature. It is also intended as a reference for scientists active in magnetism research, providing readers with novel trends and achievements in magnetism. Volume 22 comprises topical review articles covering perovskite manganites and their modifications, the magnetocaloric effect in intermetallic compounds and alloys, the scaling potential of particulate media in magnetic tape recording and layered iron superconductor systems. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material within the framework of physics, chemistry and material science.
Composed of topical review articles written by leading authoritiesIntroduces given topics in the field of magnetismProvides the reader with novel trends and achievements in magnetism

High density digital magnetic and magneto-optical storage devices are widely used in audio, video, and data processing information technology, as well as in CAD/CAM computer systems. These widespread uses generate a continually increasing demand for both increased information storage densities and capacities, and for reduced access times. Hence, the materials engineering of high density storage media, with a high signal to noise ratio, and the associated design of sophisticated read and write heads, form the basis of major technological research. This research is especially complex because, ideally, the recorded information should be both erasable and, at the same time, secure and accessible over periods of many decades. As a result, research on these complex problems requires a multidisciplinary approach which utilizes the expertise in such widely differing fields as organic, inorganic, and solid state chemistry, metallurgy, solid state physics, electrical and mechanical engineering, and systems analysis. Often, further research specialization is necessary in each of these different disciplines. For instance, solid state physics and chemistry address the problems of crystallographic structure and phase diagram determination, magnetism, and optics, but more advanced research methods, such as high resolution electron microscopy and electronic band structure calculations, are necessary to understand the microstructure of particulate recording media or the electronic spectra of magneto-optical recording media.

It is well known that the density of molecular hydrogen can be increased by compression and/or cooling, the ultimate limit in density being that of liquid hydrogen. It is less well known that hydrogen densities of twice that of liquid hydrogen can be obtained by intercalating hydrogen gas into metals. The explanation of this unusual paradox is that the absorption of molecular hydrogen, which in TiFe and LaNis is reversible and occurs at ambient temperature and pressure, involves the formation of hydrogen atoms at the surface of a metal. The adsorbed hydrogen atom then donates its electron to the metal conduction band and migrates into the metal as the much smaller proton. These protons are easily accomodated in interstitial sites in the metal lattice, and the resulting metal hydrides can be thought of as compounds formed by the reaction of hydrogen with metals, alloys, and intermetallic compounds. The practical applications of metal hydrides span a wide range of technologies, a range which may be subdivided on the basis of the hydride property on which the application is based. The capacity of the metal hydrides for hydrogen absorption is the basis for batteries as well as for hydrogen storage, gettering, and purification. The temperature-pressure characteristics of metal hydrides are the basis for hydrogen compressors, sensors, and actuators. The latent heat of the hydride formation is the basis for heat storage, heat pumps, and refrigerators.

In this book, the fundamentals of magnetism are treated, starting at an introductory level. The origin of magnetic moments, the response to an applied magnetic field, and the various interactions giving rise to different types of magnetic ordering in solids are presented and many examples are given. Crystalline-electric-field effects are treated at a level that is sufficient to provide the basic knowledge necessary in understanding the properties of materials in which these effects play a role. Itinerant-electron magnetism is presented on a similar basis. Particular attention has been given to magnetocrystalline magnetic anisotropy and the magnetocaloric effect. Also, the usual techniques for magnetic measurements are presented. About half of the book is devoted to magnetic materials and the properties that make them suitable for numerous applications. The state of the art is presented of permanent magnets, high-density recording materials, soft-magnetic materials, Invar alloys and magnetostrictive materials. Many references are given.

Handbook of Magnetic Materials covers the expansion of magnetism over the last few decades and its applications in research, notably the magnetism of several classes of novel materials that share with truly ferromagnetic materials the presence of magnetic moments. Volume 24 of the Handbook of Magnetic Materials, much like the preceding volumes, has a dual purpose. With contributions from leading authorities in the field, it includes a variety of self-contained introductions to a given area in the field of magnetism without requiring recourse to the published literature. The book is an ideal reference for scientists active in magnetism research, providing readers with novel trends and achievements in magnetism. Each article contains an extensive description given in graphical, as well as, tabular form, with much emphasis placed on the discussion of the experimental material within the framework of physics, chemistry, and material science.

Handbook of Magnetic Materials covers the expansion of magnetism over the last few decades and its applications in research, notably the magnetism of several classes of novel materials that share with truly ferromagnetic materials the presence of magnetic moments. The book is an ideal reference for scientists active in magnetism research, providing readers with novel trends and achievements in magnetism. Each article contains an extensive description given in graphical and tabular form, with much emphasis placed on the discussion of the experimental material within the framework of physics, chemistry, and material science.

Over the last few decades magnetism has seen an enormous expansion into a variety of different areas of research, notably the magnetism of several classes of novel materials that share with truly ferromagnetic materials only the presence of magnetic moments. Volume 23 of the Handbook of Magnetic Materials, like the preceding volumes, has a dual purpose. With contributions from leading authorities in the field, it includes a variety of self-contained introductions to a given area in the field of magnetism without requiring recourse to the published literature. It is also a reference for scientists active in magnetism research, providing readers with novel trends and achievements in magnetism. In each of these articles an extensive description is given in graphical as well as in tabular form, with much emphasis being placed on the discussion of the experimental material within the framework of physics, chemistry and material science.

Volume 13 of the Handbook of Magnetic Materials, as the preceding volumes, has a dual purpose. As a textbook it is intended to be of assistance to those who wish to be introduced to a given topic in the field of magnetism without the need to read the vast amount of literature published. As a work of reference it is intended for scientists active in magnetism research. To this dual purpose, Volume 13 of the Handbook is composed of topical review articles written by leading authorities. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material in the framework of physics, chemistry and material science. In Chapter 1 of this volume a general review of the experimental work on interlayer exchange coupling is presented along with a discussion of the current understanding of this field. There exists an extensive amount of scientific efforts devoted to 4f and 5f systems, including experimental and theoretical, as well as basic and applied research. Chapter 2 aims at reviewing a part of these efforts from the viewpoint of microscopic theory. Special attention is paid to the many new developments in the field. One of the intentions is to bring to the fore the darker areas of DFT theory applications. A review of novel experimental results and first-principle energy-band calculations of MOKE spectra will be presented in Chapter 3. Conventional co-operative phenomena, such as long-range order and elementary excitation, have realisations in nonmagnetic situations. This applies also to the phenomena of geometrical frustration. In Chapter 4 this topic is addressed by developing the basic principles underlying the magnetic phenomena.