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A low-dimensional magnet is a key to the next generation of electronic devices. In some respects, low-dimensional magnets refer to nanomagnets (nanostructured magnets) or single-molecule magnets (molecular nanomagnets). They also include the group of magnetic nanoparticles, which have been widely used in biomedicine, technology, industries, and environmental remediation.Low-dimensional magnetic materials can be used effectively in the future in powerful computers (hard drives, magnetic random-access memory, ultra-low power consumption switches, etc.). The properties of these materials largely depend on the doping level, phase, defects, and morphology. This book covers various nanomagnets and magnetic materials. The basic concepts, various synthetic approaches, characterizations, and mathematical understanding of nanomaterials are provided. Some fundamental applications of 1D, 2D, and 3D materials are covered.This book provides the fundamentals of low-dimensional magnets along with synthesis, theories, structure-property relations, and applications of ferromagnetic nanomaterials. This book broadens our fundamental understanding of ferromagnetism and mechanisms for realization and advancement in devices with improved energy efficiency and high storage capacity.

Frustrated spin systems have been first investigated five decades ago. Well-known examples include the Ising model on the antiferromagnetic triangular lattice studied by G H Wannier in 1950 and the Heisenberg helical structure discovered independently by A Yoshimori, J Villainn and T A Kaplan in 1959. However, extensive investigations on frustrated spin systems have really started with the concept of frustration introduced at the same time by G Toulouse and by J Villain in 1977 in the context of spin glasses. The frustration is generated by the competition of different kinds of interaction and/or by the lattice geometry. As a result, in the ground state all bonds are not fully satisfied. In frustrated Ising spin systems, a number of spins behave as free spins. In frustrated vector spin systems, the ground-state configuration is usually non-collinear. The ground state of frustrated spin systems is therefore highly degenerate and new induced symmetries give rise to unexpected behaviors at finite temperatures. Many properties of frustrated systems are still not well understood at present. Theoretically, recent studies shown in this book reveal that established theories, numerical simulations as well as experimental techniques have encountered many difficulties in dealing with frustrated systems. In some sense, frustrated systems provide an excellent testing ground for approximations and theories. Experimentally, more and more frustrated materials are discovered with interesting properties for applications.

Recent Advances in Topological Ferroics and Their Dynamics, Volume 70 in the Solid State Physics series, provides the latest information on the branch of physics that is primarily devoted to the study of matter in its solid phase, especially at the atomic level. This prestigious serial presents timely and state-of-the-art reviews pertaining to all aspects of solid state physics. - Contains contributions from leading authorities in the study of solid state physics, especially at the atomic level - Informs and updates on all the latest developments in the field - Presents timely, state-of-the-art reviews pertaining to all aspects of solid state physics

This book presents a theoretical framework for magnetism in ferromagnetic metals and alloys at finite temperatures. The objective of the book is twofold. First, it gives a detailed presentation of the dynamic spin-fluctuation theory that takes into account both local and long-wave spin fluctuations with any frequency. The authors provide a detailed explanation of the fundamental role of quantum spin fluctuations in the mechanism of metallic magnetism and illustrate the theory with concrete examples. The second objective of the book is to give an accurate and self-contained presentation of many-body techniques such as the functional integral method and Green's functions, via a number of worked examples. These computational methods are of great use to solid state physicists working in a range of specialties.The book is intended primarily for researchers, but can also be used as textbook. The introductory chapters offer clear and complete derivations of the fundamentals, which makes the presentation self-contained. The main text is followed by a number of well-organized appendices that contain a detailed presentation of the necessary many-body techniques and computational methods. The book also includes a list of symbols and detailed index. This volume will be of interest to a wide range of physicists interested in magnetism and solid state physics in general, both theoreticians and experimentalists.

'a very detailed book on multiferroics that will be useful for PhD students and researchers interested in this emerging field of materials science'—Dr. Wilfrid Prellier, Research Director, CNRS, Caen, FranceMultiferroics has emerged as one of the hottest topics in solid state physics in this millennium. The coexistence of multiple ferroic/antiferroic properties makes them useful both for fundamental studies and practical applications such as revolutionary new memory technologies and next-generation spintronics devices. This book provides an historical introduction to the field, followed by a summary of recent progress in single-phase multiferroics (type-I and type-II), multiferroic composites (bulk and nano composites), and emerging areas such as domain walls and vortices. Each chapter addresses potential technological implications. There is also a section dedicated to theoretical approaches, both phenomenological and first-principles calculations.

The book comprises six chapters which deal with the critical currents and the ferromagnetism-superconductivity coexistence in high-Tc oxides. It begins by gathering key data for superconducting state and the fundamental properties of the conventional superconductors, followed by a recap of the basic theories of superconductivity. It then discusses

Electron correlation is an important phenomenon of solid-state physics, which is actively studied both by experimentalists for the rich material properties which result from it and by theoreticians which face a lot of open questions on the way to a succesful many-body description of electron systems where the Coulomb interaction plays an important role. Ferromagnetic cobalt is an interesting candidate for the study of electron correlation, since the exchange interaction splits the band structure into majority-spin and minority-spin bands, which differ considerably in the strength of the electron-electron interaction.Using a revolutionary, parallelized approach to spin-resolved photoemission with an efficiency 3 to 4 orders of magnitude higher than previously possible, the spin-dependent manifestations of the electron correlation are revealed in unprecedented detail, allowing for a characterization of the self energy. As an additional phenomenon of the electron correlation, unusual waterfall features, previously only observed in superconductors, occur in the photoemission spectra of cobalt. Further subjects include a comprehensive mapping of the fcc cobalt Fermi surface and an investigation of unoccupied quantum well states in ultrathin cobalt films on copper accessed by spin-resolved, non-linear photoemission. The principle of the imaging spin filter and the data analysis routine are discussed in-depth in a dedicated chapter.

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.

This book mainly focuses on the investigation of the electric-field control of magnetism and spin-dependent transportation based on a Co40Fe40B20(CoFeB)/Pb(Mg1/3Nb2/3)0.7Ti0.3O3(PMN-PT) multiferroic heterostructure. Methods of characterization and analysis of the multiferroic properties with in situ electric fields are induced to detect the direct magnetoelectric (ME) coupling. A switchable and non-volatile electric field control of magnetization in CoFeB/PMN-PT(001) structures is observed at room temperature, and the mechanism of direct coupling between the ferroelectric domain and ferromagnetic film due to the combined action of 109° ferroelastic domain switching in PMN-PT and the absence of magnetocrystalline anisotropy in CoFeB is demonstrated. Moreover, the electric-field control of giant magnetoresistance is achieved in a CoFeB-based spin valve deposited on top of (011) oriented PMN-PT, which offers an avenue for implementing electric-writing and magnetic-reading random access memory at room temperature. Readers will learn the basic properties of multiferroic materials, many useful techniques related to characterizing multiferroics and the interesting ME effect in CoFeB/PMN-PT structures, which is significant for applications.

Ferrofluids, are strange materials that are part liquid, part magnet, and which solidify when exposed to magnetic fields. They consist of nanometer-sized magnetic particles dispersed in a nonmagnetic fluid such as water or kerosene and form a magnetic liquid. Ferrofluids are stable colloidal suspensions of nanosized magnetic materials in a suitable basefluid. They can be synthesized with or with out suitable surface coatings. The properties are greatly influenced by the grain size, carrier fluid chosen, and composition of the magnetic material and concentration of them in the fluid. Their flow and properties can be tuned with the application of an external magnetic field. The application potential of ferrofluids is enormous. They are important templates, from the fundamental physics point of view, to study the magnetism of non-interacting nanodomains. Also by tuning the concentration of this system, the effect of interaction also could be studied. They are also ideal templates for studying the quantum confinement effects in nanomagnetic materials. Hence, optically they are ideal systems as the grain size approaches the Bohr radius limit, high quantum confinement and induced blue shift can make them optically more transparent, and this confined exciton can assist in non-linear absorptions. As a random media, this can offer induced scattering which can make them good optical limiters owing to their high shelf life and stability against agglomeration.

This book covers all principal aspects of currently investigated frustrated systems, from exactly solved frustrated models to real experimental frustrated systems, going through renormalization group treatment, Monte Carlo investigation of frustrated classical Ising and vector spin models, low-dimensional systems, spin ice and quantum spin glass. The reader can — within a single book — obtain a global view of the current research development in the field of frustrated systems.This new edition is updated with recent theoretical, numerical and experimental developments in the field of frustrated spin systems. The first edition of the book appeared in 2005. In this edition, more recent works until 2012 are reviewed. It contains nine chapters written by researchers who have actively contributed to the field. Many results are from recent works of the authors.The book is intended for postgraduate students as well as researchers in statistical physics, magnetism, materials science and various domains where real systems can be described with the spin language. Explicit demonstrations of formulas and full arguments leading to important results are given where it is possible to do so.

Introduction Chapter 1 - Explanation of Ferromagnetism Chapter 2 - Ising Model Chapter 3 - Ferromagnetic Materials

This book covers both basic physics of ferromagnetism, such as magnetic moment, exchange coupling, magnetic anisotropy, and recent progress in advanced ferromagnetic materials. Special focus is placed on NdFeB permanent magnets and the materials studied in the field of spintronics (explaining the development of tunnel magnetoresistance effect through the so-called giant magnetoresistance effect).

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 matte

Quantum dynamics underlies macroscopic systems exhibiting some kind of ordering, such as superconductors, ferromagnets and crystals. Even large scale structures in the Universe and ordering in biological systems appear to be the manifestation of microscopic dynamics ruling their elementary components. The scope of this book is to answer questions such as: how it happens that the mesoscopic/macroscopic scale and stability characterizing those systems are dynamically generated out of the microscopic scale of fluctuating quantum components; how quantum particles coexist and interact with classically behaving macroscopic objects, e.g. vortices, magnetic domains and other topological defects. The quantum origin of topological defects and their interaction with quanta is a crucial issue for the understanding of symmetry breaking phase transitions and structure formation in a wide range of systems from condensed matter to cosmology. Deliberately not discussing other important problems, primarily renormalization problems, this book provides answers to such questions in a unitary, self-consistent physical and mathematical framework, which makes it unique in the panorama of existing texts on a similar subject. Crystals, ferromagnets and superconductors appear to be macroscopic quantum systems, i.e. their macroscopic properties cannot be explained without recourse to the underlying quantum dynamics. Recognizing that quantum field dynamics is not confined to the microscopic world is one of the achievements of this book, also marking its difference from other texts. The combined use of algebraic methods, and operator and functional formalism constitutes another distinctive, valuable feature.

Summary: The present volume "New Trends in Lithium Niobate: From Bulk to Nanocrystals" contains the materials of a Special Issue of the MDPI journal Crystals dedicated to the memory of Prof. Dr. Ortwin F. Schirmer and provides a new synopsis of his research focusing on LiNbO3. It also includes recent developments, exemplifying the continued interest in this outstanding ferroelectric, non-linear optical and holographic crystal as a workhorse for testing and realizing new ideas and applications.This book starts with reviews on intrinsic and extrinsic crystal defects in LiNbO3 of single-crystal, thin-film or nano-powder forms, studied by various optical, magnetic resonance and nuclear methods, clarifying in particular the reasons for the suppression of anion vacancy formation upon thermal reduction, mechano-chemical processing or irradiations of various types. The reviews are followed by research papers on the experimental and theoretical investigation of small polarons, together with recent results on the properties of Li(Nb,Ta)O3 mixed crystals. Among the various contributions dealing with nonlinear optical applications, papers on device development, entangled photon pair generation and thin films on the Lithium Niobate On Insulator (LNOI) platform can also be found.