Spin Arrangements and Crystal Structure, Domains, and Micromagnetics


Book Description

Spin Arrangements and Crystal Structure, Domains, and Micromagnetics deals with cooperative phenomena characterized by ordered arrangements of magnetic moments subject to strong mutual interactions. The emphasis is on the ferromagnetism, ferrimagnetism, and antiferromagnetism of magnetically ordered materials such as insulators and metals. Both theoretical and experimental points of view are presented. Comprised of 12 chapters, this volume begins with an introduction to magnetism and crystal structure in nonmetals, followed by an evaluation of exchange interactions from experimental data. Subsequent chapters focus on the theory of neutron scattering by magnetic crystals; spin configuration of ionic structures; spin arrangements in metals; and permanent magnet materials. Fine particles, thin films, and exchange anisotropy are also considered, with particular reference to the effects of finite dimensions and interfaces on the basic properties of ferromagnets. The book also examines micromagnetics; domains and domain walls; the structure and switching of permalloy films; magnetization reversal in nonmetallic ferromagnets; and preparation and crystal synthesis of magnetic oxides. This book will be a useful resource for professionals and students with physics or chemistry backgrounds.













The Effects of Gas Occlusions and Strains on the Magnetic Properties of Thin Permalloy Films


Book Description

This report comprises a selective survey of the present knowledge of the effects of occluded gases and strains on the magnetic properties of Permalloy films, particularlly those which have significance for computer switching applications. Other possible techniques for accomplishing future computer switching functions and magnetic film properties are reviewed. Bulk properties are described and compared with corresponding thin film properties. The magnetic properties of epitaxial Permalloy, epitaxial nickel, epitaxial iron, polycrystalline nickel, and polycrystalline iron films are discussed. The effects of various occluded gases on magnetic film properties are summarized. Stresses present in evaporated films and their significance in determining the magnetic properties of thin films are considered. A selected bibliography of 548 references is included. (Author).




Magnetism


Book Description




Magnetic Small-Angle Neutron Scattering


Book Description

This monograph provides the first extensive treatment of magnetic small-angle neutron scattering (SANS). The theoretical background required to compute magnetic SANS cross sections and correlation functions related to long-wavelength magnetization structures is laid out. The concepts are scrutinized based on the discussion of experimental neutron data. Regarding prior background knowledge, some familiarity with the basic magnetic interactions and phenomena as well as scattering theory is desired. Besides exposing the different origins of magnetic SANS, and furnishing the basics of the magnetic SANS technique in early chapters, a large part of the book is devoted to a comprehensive treatment of the continuum theory of micromagnetics, as it is relevant for the study of the elastic magnetic SANS cross section. Analytical expressions for the magnetization Fourier components allow to highlight the essential features of magnetic SANS and to analyze experimental data both in reciprocal, as well as in real space. Later chapters provide an overview on the magnetic SANS of nanoparticles and so-called complex systems (e.g., ferrofluids, magnetic steels, spin glasses and amorphous magnets). It is this subfield where major progress is expected to be made in the coming years, mainly via the increased usage of numerical micromagnetic simulations (Chapter 7), which is a very promising approach for the understanding of the magnetic SANS from systems exhibiting nanoscale spin inhomogeneity.




NBS Technical Note


Book Description




The NBS Alloy Data Center


Book Description

The Alloy Data Center, part of the National Standard Reference Data System, has two primary functions. One is to stimulate cooperation and coordination among the existing data centers in the area of the physical properties of well characterized alloys. The final data generated by these centers for publication should be consistent with one another where correlation or possible overlap exists. The other purpose is the collection (from publications as well as private communications), evaluation, and publication of data in some areas where special competence exists in the Alloy Physics Section. Of interest to the center are metals, semimetals, intermetallic compounds, and alloys. Excluded are those materials which have ill-defined constitutions and heat treatments. An automated system was developed to meet the bibliographic needs of the center. This system will be described as well as the specific properties of interest. The system presently contains a complete annotated file dealing with NMR Knight shift measurements. The soft X-ray spectroscopy compilation is being kept up-to-date with the same system. (Author).