bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetism Of Compounds
Authors: Chikazumi Sōshin , Graham, Jr C D 
Published: November 2023

Abstract
In this chapter, we discuss the magnetism of compounds composed of electropositive3dtransition elements or4frare earth elements combined with electronegative elements which belong to the Illb, IVb, Vb, VIb and Vllb groups. The electronegative elements which belong to these groups are listed in Table 10.1. Some elements such as Al, Ga, In, Tl, Sn and Pb, which belong to Illb and IVb groups, have metallic character, so that they could have been treated as intermetallic compounds in Section 8.4.
Technical Magnetization
Authors: Chikazumi Sōshin , Graham, Jr C D 
Published: November 2023

Abstract
When a magnetic material is subjected to an increasing magnetic field, its magnetization is increased and finally reaches a limiting value called thesaturation magnetization.This process is calledtechnical magnetization,because it is essentially achieved by a change in the direction of domain magnetization and can be distinguished from a change in the intensity of spontaneous magnetization.
Various Phenomena Associated With Magnetization
Authors: Chikazumi Sōshin , Graham, Jr C D 
Published: November 2023

Abstract
In magnetic materials, the spins can undergo thermal motion. Therefore magnetic materials exhibit an additional or ‘anomalous’ specific heat in addition to the normal specific heat caused by the thermal motion of the crystal lattice (see Section 6.1). In other words, magnetic materials have additional entropy due to the presence of spins. This entropy is controllable by an external magnetic field.
Engineering Applications Of Magnetic Materials
Authors: Chikazumi Sōshin , Graham, Jr C D 
Published: November 2023

Abstract
Engineering applications of ferromagnetic materials are divided into three major categories: first is soft magnetic materials for AC applications in magnetic cores of transformers, motors, inductors and related devices. For this purpose, high permeability, low coercive field, and low hysteresis loss are required. SecmLd is hard magnetic materials for permanent magnets. For this purpose, high coercive field, high residual magnetization, and accordingly high energy product (see Section 1.6) are required. Third is the semi-hard magnetic materials for magnetic recording. For this purpose, moderately high coercive field and high residual magnetization are required.
Summary Tables Of Particle Properties
Authors: Group Particle Data 
Published: November 2023

Abstract
In keeping with the current interest in tests of conservation laws, we collect together a Table of experimental limits on all weak and electromagnetic decays, mass differences, and moments, and on a few reactions, whose observation would violate conservation laws. The Table is given only in the full Review of Particle Properties, not in the Particle Physics Booklet. For the benefit of Booklet readers, we include the best limits from the Table in the following text.
The one-dimensional electron gas
Authors: Kelly M J 
Published: November 2023

Abstract
The role of 2D systems in elucidating details of quantum transport in semiconductors was a key theme of the previous chapter, which concluded with an investigation of the transition between three and two dimensions. Until recently, 1D systems have been the playground of the theorist; some of the most intractable problems in many-body physics admit analytical or transparent numerical solutions (Lieb and Mattis 1966). It has long been appreciated that an infinitesimal amount of disorder is sufficient to localize all electron states in one dimension (Mott and Twose 1961). Thouless’s ideas, described in Chapter 4, Section 4.3.2, were advanced on the basis of 1D arguments. Once the extent of the applications of Q2D systems had been appreciated (cf. Chapter 16), attempts were made to extend the technology to realize QlD systems and to investigate the Q2D-Q1D transition. It has been important to find ways to confine the Q2D electron gas spatially in one of the two in-plane directions; an increasing number of methods have been found. In this chapter, we mirror the previous one, and describe the wealth of phenomena in QlD systems, as investigated in the 1D electron gas (lDEG). In later chapters (11, 12, and 15) we consider other aspects of physics in QlD systems not considered here.
Hot electron phenomena
Authors: Kelly M J 
Published: November 2023

Abstract
Much interesting physics, and most device applications, are associated with carriers that have been excited in some manner to have an energy well in excess of their energy when in thermal equilibrium. In some cases the carriers behave in a manner that can be associated with an elevated temperature, giving rise to the name hot carrier. The name is used more widely to refer to any highly excited carrier. We discussed the velocity-field curves for bulk Si and GaAs in Chapter 1, Section 1.7. We described the transition from Ohm’s law behaviour at low electric fields, where the carriers are little perturbed from equilibrium, through to the regime of saturated drift velocity at high electric fields. Here the carriers are in a steady state; they are highly excited but are giving up their excess energy to the lattice (via phonon emission) at the same rate that they acquire energy from the electric field. We also introduced the idea of avalanching in very high electric fields where very hot electrons excite further electron-hole pairs, and we related the uncontrolled form of this phenomenon to dielectric breakdown. In Chapter 5, Section 5.6, we described the reduction of mobility seen in a 2DEG as a function of increased applied field. In Chapter 6, Section 6.6, we briefly discussed the current-voltage characteristics of a QlDEG in the presence of a strong electric field where eventually there is less current for a greater applied bias. In this chapter we gather together the main hot carrier effects in semiconductor multilayers, associated with the non-linear response to strong electric or optical fields. Using hetero junctions, one can inject carriers from wider-gap into narrowergap semiconductors. The injected carriers are initially very hot, having an initial velocity as much as 10 times that of the saturated drift velocity, and we can study the detailed mechanisms by which they lose their excess energy and momenta and return to thermal equilibrium temperatures. The modification to the density of states in less than three dimensions slows down the rate of relaxation of hot carriers.
Superlattices and minibands
Authors: Kelly M J 
Published: November 2023

Abstract
The repetition of a pair or more of multilayers (say repeats of m monolayers of GaAs and n monolayers of AlAs) introduces a new periodicity into a crystal structure. The new underlying lattice is called a super lattice; it retains the lattice constant of GaAs in the plane of the layers, but has a new lattice constant in the perpendicular direction set by m&lt;-GaAs + nd AlAs, where the d i are the interlayer spacings of the component materials in the direction of the crystal growth. There is an interaction between the discrete bound states found in 1D wells when they are placed adjacent to each other. A narrow band, called a miniband, is formed in the direction of the crystal growth. Its width in energy is determined by the thicknesses and heights of the AlGaAs or AlAs barriers, while its mean energy is determined by the thickness of the GaAs layers. The attraction of super lattices is that new crystals are being prepared which are not available in nature. We can engineer the electronic and optical properties of these crystals at the stage of preparing the growth specification for the multilayers. In this chapter we discuss the theory and experimental results relating to superlattices and minibands.
Vibrational, thermal, and other properties
Authors: Kelly M J 
Published: November 2023

Abstract
So far, we have concentrated on the electronic and optical properties of semiconductor multilayers. In this chapter, we consider the vibrational properties of the host lattice, including the effects of the multilayers themselves. The lattice vibrational dispersion relations for bulk GaAs and AlAs are given in Chapter 1, Fig. 1.6. Such phonon spectra are derived from theories of varying complexity, in an attempt to reproduce experimental data in great detail, but a simple model involving bond-stretching and bondbending forces is sufficient to generate a semi quantitative understanding (Harrison 1980). We can use such a model to describe the lattice vibrations of a superlattice, and the various acoustic, optic, and interface phonon modes that can arise. We describe a number of optical and transport experiments used to detect phonons. The interactions between electrons and phonons play an important role, already considered in Chapter 7, in relaxing hot carriers that have been excited optically or with an electric field.
Silicon and silicon hetero junctions
Authors: Kelly M J 
Published: November 2023

Abstract
The generation and detection of microwave signals for both communications and radar is one area of application where devices with hetero junctions and precision semiconductor multilayers have found rapid deployment. These have been largely two-terminal devices. We begin this chapter with a short introduction to the basic device principles, and then take several diode structures and show how the physics of the preceding chapters has been translated into commercially successful devices. One feature of microwave systems has helped this rapid exploitation, namely that many of the highest performance systems are still hybrid, and there is an immediate role for improved discrete devices in each part of the system. This is particularly so, as the new generation devices have similar radiofrequency impedance properties as the earlier devices, and can therefore be used as instant retrofits. Indeed, the superior properties of the new generation devices have been exploited to improve the overall system specification or to relax the burden on some other critical component of the system. While the discrete devices have improved efficiency or sensitivity, as appropriate, a whole range of secondary attributes are also important. For example the sensitivity of the new devices to ambient temperature is much reduced, and the dynamic range and robustness increased, so that a system can be simplified by dispensing with circuits that compensate for temperature variations or protect formerly delicate components. In monolithic integrated circuit applications, many extra constraints in terms of overall chip compatibility must be satisfied, and it may be some time before some of these discrete devices are deployed in such circuits. The debate between hybrid technology and monolithic integration is active and ongoing, typified by the systems proposed for automotive radar. The hybrid systems are available earlier and will compete on cost until a one-chip solution is found.
Towards 2000
Authors: Kelly M J 
Published: November 2023

Abstract
Contemporary semiconductor science and technology has a momentum that allows one to make predictions on the progress over the next few years based on the experience of the last 20 years. We are concerned in this chapter with the future of materials, technology, structures, physics, and devices in mainstream multilayer semiconductor science and technology. In the concluding chapter, we consider some of the radical alternatives to this mainstream that are being pursued in research and development. In conventional ultra-largescale-integration Si technology, the current developments in the various fabrication steps (lithography, etching, metallization, etc.)will ensure a steady progress in the memory and computational capability through this decade and into the next century. Extrapolations from the 1970s and 1980s are a reasonable guide for the 1990s, as far as the technology is concerned (but see Section 21.8 for a more global picture). The science in Si technology is increasingly concerned with the effects of the intrinsic small scale of the devices, particularly including those of high electric fields, and we review this area more fully in section 21.7. The advances in multilayer semiconductor science have relied on the technology for fabricating the test structures, and the interdependence of science, technology, and devices is becoming more complete, a principal reason for the structure of this book. The science and technology of low-dimensional semiconductors is having a large impact on the science of metrology, and we include a discussion of this in the penultimate section of this chapter.
Polyelectrolytes in solution
Authors: Sedlák Marián 
Published: November 2023

Abstract
Polyelectrolytes can be defined as compounds which are macromolecules or supramolecular entities carrying a large number of ionizable groups. These groups dissociate in solution under certain conditions. As a result, the macro molecule becomes highly charged and is referred to as a polyion. The dissociation of each group on the polyion results in the creation of one counterion of opposite charge with respect to the polyion. If the polyion charge is Q = Ze (e being the electron charge), then each polyion is ‘accompanied’ by Z counterions. Figure 4.1 shows schematically the situation in a polyelectrolyte solution.
Combined static and dynamic light scattering
Authors: Burchard Walther 
Published: November 2023

Abstract
Dynamic light scattering (DLS) has been applied in polymer and colloid science for about 30 years and many review articles and several books have been published on the topic Although the theory is well developed, there are probably several reasons why another review is timely. The first is that research in polymer science has been mainly concerned with flexible linear chains or with rigid rods in the dilute and semi-dilute solution regimes. Recently, however, polymer scientists have become increasingly interested in the behaviour and characterization of other polymeric architectures such as semi-flexible or worm-like chains, cyclic macromolecules, star-branched macromolecules, randomly branched and hyper-branched structures, but systematic studies have not been made and an overview has not yet appeared.
Light scattering and chromatography in combination
Authors: Lloyd Linda L , Kennedy John F , Knill Charles J 
Published: November 2023

Abstract
The need to understand the relationships between the physicochemical characteristics of macromolecules has been the driving force for the development of instrumentation for the characterization of such molecules. Polymer chemists and biochemists have constantly strived for analytical instrumentation and methods which enable molecular weight and structure information to be generated, as it has long been recognized that these are fundamental properties which influence the physical properties of polymeric materials. Many methods have been utilized, such as thermogravimetric analysis, osmometry, viscometry, and light scattering, which provide information on the bulk characteristics of a material, and separation systems, such as liquid chromatography, which attempt to separate the molecules prior to characterization. By combining the separation methodologies with the characterization methods, an exceptionally powerful method becomes available for determining not just bulk characteristics but also distributions of these characteristics.
Regularization
Authors: Ripka Georges 
Published: November 2023

Abstract
The regularization of an effective theory is not just a mathematical trick designed to eliminate whatever infinities happen to occur. It is a physical process and, as such, an integral part of a model. If we knew how to derive a low energy effective theory from QCD, we would know how the theory becomes regularized. For example, the instanton induced interaction (section 3.2) involves delocalized fields, which introduce a non-locality which in turn regularizes the effective theory. More often than not, we adopt a given regularization scheme for convenience. This is tantamount to admitting our ignorance as to its origin. Regularization of an effective theory should also be distinguished from renormalization. A renormalizable model has the attractive feature that it can predict observables which do not depend on the cut-off, which can be taken to infinity. Many of the un-pleasant properties encountered when an effective theory is regularized disappear when the cut-off is sent to infinity.
Correlation Functions: Basic Properties
Authors: Ripka Georges 
Published: November 2023

Abstract
Correlation functions are ground state or thermal expectation values of timeordered products of operators. Two-point correlation functions are also commonly called propagators or Green’s functions. They allow us to study the response of a system to specific probes. The poles of correlation functions correspond to the eigenvalues of the hamiltonian and to on-shell masses of mesons and baryons. The residues at the poles correspond to transition matrix elements of operators between the ground state and the excited states. Correlation functions are thus closely related to experimental data. The application of correlation functions to hadronic physics is reviewed in [9, 92, 93]. Correlation functions are also the objects which are calculated (it is often said that they are ‘measured’) in QCD lattice calculations [10, 94].
Rotations Of Solitons In Flavor Space
Authors: Ripka Georges 
Published: November 2023

Abstract
The underlying physical picture is that of a slowly rotating deformed state. Indeed, if we rotate a hedgehog solution, a degenerate solution is obtained. There is no restoring force opposing spatial rotations. The only energy acquired by the rotation is a kinetic energy, proportional to the squared angular momentum and inversely proportional to a moment of inertia. One expects then that the low-lying excited states of the system, those which dominate the partition function, should consist of a rotational band generated by the rotating soliton. However, further effects need to be taken into account. The angular momentum acquired by the rotating soliton is quantized and cannot therefore take arbitrarily small values. The rotation gives rise to Coriolis forces which deform the soliton. They tend to align the spins with the rotation axis.
Introduction
Authors: Coey J M D 
Published: November 2023

Abstract
The magnetization of a piece of ferromagnetic material has its origin in the spin and orbital magnetic moments of the atomic electrons. These moments arise from the angular momentum of the electrons. Nuclear magnetism is negligible by comparison. Summing the elementary contributions in a volume that is large on the atomic scale, one defines a local magnetization vector, M, that represents the magnetic moment per unit volume. In general, M is not uniform throughout a sample of macroscopic dimensions, but when the sum is carried out within a domain, the magnitude of M, known as the spontaneous magnetization Ms, is uniform; the direction of magnetization varies from domain to domain and typically lies along a crystallographic axis.
Interstitial modification
Authors: Skomski R 
Published: November 2023

Abstract
In 1990, Coey and Sun [Coe90] discovered that the magnetic properties of Sm 2Fe 17 are dramatically altered by nitrogen introduced from a gas in a low-temperature reaction. In the simplest case, gas-phase nitrogenation is conducted on finely ground Sm2Fe17 powder in a pressure of about 1 bar nitrogen gas; at typical nitrogenation temperatures (400-500 °C) the nitrogenation reaction takes a few hours, depending on the particle size.
Actuators
Authors: Howe D 
Published: November 2023

Abstract
The emergence of high-energy rare-earth permanent magnets has facilitated the development of new and improved forms of limited motion actuators, both linear and rotary. Applications span all market sectors, from disk head drives and industrial robots to pneumatic pumps and automatic car door locks. Thus, requirements regarding power and displacement, speed of response, positional accuracy and duty cycle are very wide. In general, however, all actuators provide a force acting directly to move a load, and thus tend to be simpler electromagnetic structures than rotary motors with gears.
A non-linear oscillator in an optical field
Authors: Akhmanov S A , Nikitin S YU 
Published: November 2023

Abstract
A model of a non-linear oscillator. The perturbation method. An oscillator with quadratic non-linearity. Optical second-harmonic generation. An oscillator with cubic non-linearity. The dependence of the oscillation frequency on amplitude. Oscillation phase variations caused by an external field. Self-action effects of light: self-focusing of optical beams and self-modulation of pulses. Optical third-harmonic generation. Non-linear resonance and hysteresis. Optical stability. Parametric generation of light. Parametric resonance. Raman scattering of light. A model of non-linearly bonded oscillators. A non-homogeneous ensemble of non-linear oscillators. “Photon echo”.
The Conserved-Order-Parameter Using Model
Authors: Newman M E J , Barkema G T 
Published: November 2023

Abstract
In the last two chapters we have looked in detail at the using model, which is primarily of interest as a model of a ferromagnet. In this chapter we look at a variation on the using model idea, the conserved-order-parameter using model. Although mathematically similar to the normal using model, the conserved-order-parameter using model is used to model very different systems. In particular, it can be used to study the properties of lattice gases.
Analysing Monte Carlo Data
Authors: Newman M E J , Barkema G T 
Published: November 2023

Abstract
In the preceding chapters of this book we have looked at Monte Carlo algorithms for measuring the equilibrium properties of a variety of different models. The next few chapters are devoted to an examination of Monte Carlo methods for the study of out-of-equilibrium systems. But before we embark on that particular endeavour, we are going to take a look at some techniques for the analysis of data from equilibrium simulations. There are no new Monte Carlo algorithms in this chapter, but it does describe several methods of data analysis which can significantly improve the quality of the results we extract from the raw data spit out by the algorithms of the previous chapters.
Elastic and inelastic scattering
Authors: Sakaguchi H 
Published: November 2023

Abstract
When we bombard a nucleus with a nucleon or with light ions like deuterons, 3He, a-particles, etc., various nuclear phenomena occur, including elastic scattering, inelastic scattering, nucleon transfer reactions, and projectile fragmentation, depending on the projectile species and the bombarding energy. The simplest among these phenomena—and one with the smallest amount of internal freedom—is the elastic scattering of a nucleon by a nucleus which we treat in this chapter.
In elastic scattering the target nucleus is not excited, so its initial and final states are the same. Furthermore, the initial states in such experiments are the target ground states, the charge distributions of which can be measured precisely by electron scattering. The wave function of the proton part of the target ground state is restricted and almost defined by the experiment. Thus elastic scattering is an appropriate type of reaction to use as a probe for the interactions and the dynamics which occur inside the nucleus. It is quite understandable that the first successful attempt to explain nuclear reactions microscopically began with elastic scattering.