Metallic Multilayers And Their Applications

Thin Metallic multilayer films have become an important part in today's computer technology. The giant magnetoresistance (GMR) effect, which plays a central role here, was discovered in the late 1980s. This can be essentially described as the effect of a magnetic field on the electron transport leading to significant changes in the resistance. Other aspects of multilayers systems, such as stability, growth, confinement are also addressed. Theoretical and experimental methods used in such work are described in some detail, with special emphasis on density functional and spin density functional theories. Magnetic anisotropy in thin films is also discussed while addressing unresolved issues and new results from exchange-bias experiments. * Discusses the GMR effect * What makes multilayers interesting and useful? * What are the latest discoveries in this field? * Simple insights in to the physics behind multilayers * Novel concepts at small length scales * Theoretical and experimental background

This book contains a series of lectures given in a Summer School held in Aussois (France) in September 1989. It offers a global perspective on the current state-of-the-art in the rapidly emerging field of metallic multilayered structures.

Low-dimensional materials are of fundamental interest in physics and chemistry and have also found a wide variety of technological applica tions in fields ranging from microelectronics to optics. Since 1986, several seminars and summer schools devoted to low-dimensional systems have been supported by NATO. The present one, Physics, Fabrication and Applications of Multilayered structures, brought together specialists from different fields in order to review fabrication techniques, charac terization methods, physics and applications. Artificially layered materials are attractive because alternately layering two (or more) elements, by evaporation or sputtering, is a way to obtain new materials with (hopefully) new physical properties that pure materials or alloys do not allow. These new possibilities can be ob tained in electronic transport, optics, magnetism or the reflectivity of x-rays and slow neutrons. By changing the components and the thickness of the layers one can track continuously how the new properties appear and follow the importance of the multilayer structure of the materials. In addition, with their large number of interfaces the study of inter face properties becomes easier in multilayered structures than in mono layers or bilayers. As a rule, the role of the interface quality, and also the coupling between layers, increases as the thickness of the layer decreases. Several applications at the development stage require layer thicknesses of just a few atomic layers.

This book focuses on an increasingly important area of materials science and technology, namely, the fabrication and properties of artificial materials where slabs of magnetized materials are sandwiched between slabs of nonmagnetized materials. It includes reviews by experts on the theory and descriptions of the various experimental techniques such as those using nuclear or electron spin probes, as well as optical, X-ray or neutron probes. It also reviews potential applications such as the giant magnetoresistance, and one specialized preparation technique, the electrodeposition. The various chapters are tutorial in nature, making the subject accessible to nonspecialists, as well as useful to researchers in the field. Contents: Application of Magnetic Multilayers (M Pardavi-Horvath)Magnetic Coupling in Metallic Multilayers (Y Yafet)First-Principles Calculations of Magnetic Interfaces and Multilayers (M Weinert ' S Blügel)Influence of Imperfections on the Magnetic Properties of Fe/Ag Films and Multilayers (J Pirnay et al.)NMR Studies on Magnetic Multilayers (H A M de Gronckel ' W J M de Jonge)Conversion Electron Mössbauer Spectroscopy of Magnetic Multilayers (Ch Sauer ' W Zinn)Resonance in Coupled Ferromagnetic Layer Structures (P E Wigen)Magnetic Circular X-Ray Dichroism (F Baudelet et al.)Magneto-Optical Spectra in Multilayers (K Sato)Neutron and X-Ray Diffraction Studies of Magnetic Multilayers (C F Majkrzak et al.)Giant Magnetoresistance (GMR) in Multilayers (M Pardavi-Horvath)Electrodeposited Magnetic Multilayers (M P Dariel et al.) Readership: Graduate students, professional researchers and well-educated others (eg. contract officers). keywords:Magnetic Multilayers;Circular Dichroism;Giant Magnetoresistance;Magnetic Interfaces;Magnetic Multilayers: Effect of Imperfections;Conversion Electron Mossbauer Spectroscopy;Multilayer Magnetic Coupling;Magneto-Optical Spectroscopy;Neutron Diffraction;Magnetic Xray Diffraction;Magnetic Multilayer Fabrication;Supermirrors;Magnetic Recording;RKKY Coupling;Nuclear Magnetic Resonance;Ferromagnetic Resonance

The development of electronic materials and particularly advances in semiconductor technology have played a central role in the electronics revolution by allowing the production of increasingly cheap and powerful computing equipment and advanced telecommunications devices. This Concise Encyclopedia, which incorporates relevant articles from the acclaimed Encyclopedia of Materials Science and Engineering as well as newly commissioned articles, emphasizes the materials aspects of semiconductors and the technologies important in solid-state electronics. Growth of bulk crystals and epitaxial layers are discussed in the volume and coverage is included of defects and their effects on device behavior. Metallization and passivation issues are also covered. Over 100 alphabetically arranged articles, written by world experts in the field, are each intended to serve as the first source of information on a particular aspect of electronic materials. The volume is extensively illustrated with photographs, diagrams and tables. A bibliography is provided at the end of each article to guide the reader to recent literature. A comprehensive system of cross-references, a three-level subject index and an alphabetical list of articles are included to aid readers in the abstraction of information.

Materials Research in thin and ultrathin magnetic structures is a multidisciplinary field which heavily relies on state-of-the-art growth, characterization and theoretical approaches to build a comprehensive physical picture on how magnetic properties depend on interfacial structural issues, interlayer coupling and transport phenomena. Often in this field, the critical properties and characterization required necessitates knowledge of structural and magnetic phenomena extending over several atomic planes. Atomic controlled growth techniques are required and atomic sensitivity is needed from magnetic and structural probes. This critical knowledge is vital for device applications, providing the basis for the synergistic interactions that are predominant in this field of research. This volume is the definitive reference source for anyone interested in the latest advances and results of current experimental research in ultrathin film magnetism.

This is one of the first application-orientated books on the subject. The main topics are magnetic sensors with high resolutions and magnetic read heads with high sensitivities, required for hard-disk drives with recording densities of several gigabytes. Another important subject is novel magnetic random-access memory (MRAM) with non-volatile non-destructive and radiation-hard characteristics.