Download or read book Electronic Phase Transitions written by W. Hanke and published by North Holland. This book was released on 1992 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electronic Phase Transitions deals with topics, which are presently at the forefront of scientific research in modern solid-state theory. Anderson localization, which has fundamental implications in many areas of solid-state physics as well as spin glasses, with its influence on quite different research activities such as neural networks, are two examples that are reviewed in this book. The ab initio statistical mechanics of structural phase transitions is another prime example, where the interplay and connection of two unrelated disciplines of solid-state theory - first principle electronic structure calculations and critical phenomena - has given rise to impressive new insights. Clearly, there is more and more need for accurate, stable numerical simulations of models of interacting electrons, presently discussed with great vigor in connection with high- T c superconductors where the superconducting transition is close to a magnetic transition, i.e. an antiferromagnetic spin structure. These topics and others are discussed and reviewed by leading experts in the field.
Download or read book Phase Transitions and Self Organization in Electronic and Molecular Networks written by J.C. Phillips and published by Springer Science & Business Media. This book was released on 2006-04-11 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in nanoscale science show that the properties of many materials are dominated by internal structures. In molecular cases, such as window glass and proteins, these internal structures obviously have a network character. However, in many partly disordered electronic materials, almost all attempts at understanding are based on traditional continuum models. This workshop focuses first on the phase diagrams and phase transitions of materials known to be composed of molecular networks. These phase properties characteristically contain remarkable features, such as intermediate phases that lead to reversibility windows in glass transitions as functions of composition. These features arise as a result of self-organization of the internal structures of the intermediate phases. In the protein case, this self-organization is the basis for protein folding. The second focus is on partly disordered electronic materials whose phase properties exhibit the same remarkable features. In fact, the phenomenon of High Temperature Superconductivity, discovered by Bednorz and Mueller in 1986, and now the subject of 75,000 research papers, also arises from such an intermediate phase. More recently discovered electronic phenomena, such as giant magnetoresistance, also are made possible only by the existence of such special phases. This book gives an overview of the methods and results obtained so far by studying the characteristics and properties of nanoscale self-organized networks. It demonstrates the universality of the network approach over a range of disciplines, from protein folding to the newest electronic materials.
Download or read book Electronic Phase Transitions written by Yu.V. Kopaev and published by Elsevier. This book was released on 2012-12-02 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electronic Phase Transitions deals with topics, which are presently at the forefront of scientific research in modern solid-state theory. Anderson localization, which has fundamental implications in many areas of solid-state physics as well as spin glasses, with its influence on quite different research activities such as neural networks, are two examples that are reviewed in this book. The ab initio statistical mechanics of structural phase transitions is another prime example, where the interplay and connection of two unrelated disciplines of solid-state theory - first principle electronic structure calculations and critical phenomena - has given rise to impressive new insights. Clearly, there is more and more need for accurate, stable numerical simulations of models of interacting electrons, presently discussed with great vigor in connection with high-Tc superconductors where the superconducting transition is close to a magnetic transition, i.e. an antiferromagnetic spin structure. These topics and others are discussed and reviewed by leading experts in the field.
Download or read book Phase Transitions in Materials written by Brent Fultz and published by Cambridge University Press. This book was released on 2014-08-14 with total page 589 pages. Available in PDF, EPUB and Kindle. Book excerpt: A clear, concise and rigorous textbook covering phase transitions in the context of advances in electronic structure and statistical mechanics.
Download or read book Quantum Phase Transitions written by Subir Sachdev and published by Cambridge University Press. This book was released on 2011-04-07 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describing the physical properties of quantum materials near critical points with long-range many-body quantum entanglement, this book introduces readers to the basic theory of quantum phases, their phase transitions and their observable properties. This second edition begins with a new section suitable for an introductory course on quantum phase transitions, assuming no prior knowledge of quantum field theory. It also contains several new chapters to cover important recent advances, such as the Fermi gas near unitarity, Dirac fermions, Fermi liquids and their phase transitions, quantum magnetism, and solvable models obtained from string theory. After introducing the basic theory, it moves on to a detailed description of the canonical quantum-critical phase diagram at non-zero temperatures. Finally, a variety of more complex models are explored. This book is ideal for graduate students and researchers in condensed matter physics and particle and string theory.
Download or read book Photoinduced Phase Transitions written by K. Nasu and published by World Scientific. This book was released on 2004 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new class of insulating solids was recently discovered. Whenirradiated by a few visible photons, these solids give rise to amacroscopic excited domain that has new structural and electronicorders quite different from the starting ground state. This occurrenceis called photoinduced phase transition, and this multi-authoredbook reviews recent theoretical and experimental studies of this newphenomenon.
Download or read book Lectures On Phase Transitions And The Renormalization Group written by Nigel Goldenfeld and published by CRC Press. This book was released on 2018-03-08 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering the elementary aspects of the physics of phases transitions and the renormalization group, this popular book is widely used both for core graduate statistical mechanics courses as well as for more specialized courses. Emphasizing understanding and clarity rather than technical manipulation, these lectures de-mystify the subject and show precisely "how things work." Goldenfeld keeps in mind a reader who wants to understand why things are done, what the results are, and what in principle can go wrong. The book reaches both experimentalists and theorists, students and even active researchers, and assumes only a prior knowledge of statistical mechanics at the introductory graduate level.Advanced, never-before-printed topics on the applications of renormalization group far from equilibrium and to partial differential equations add to the uniqueness of this book.
Download or read book The Physics of Phase Transitions written by Pierre Papon and published by Springer Science & Business Media. This book was released on 2007-07-27 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book occupies an important place at the crossroads of several fields central to materials sciences. The expanded second edition incorporates new developments in the states of matter physics, and includes end-of-chapter problems and complete answers.
Download or read book Electronic Phase Transitions in Transition metal Oxides written by Gerard Joseph HYLAND and published by . This book was released on 1968 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Phase Transitions and Relaxation in Systems with Competing Energy Scales written by T. Riste and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Systems with competing energy scales are widespread and exhibit rich and subtle behaviour, although their systematic study is a relatively recent activity. This text presents lectures given at a NATO Advanced Study Institute reviewing the current knowledge and understanding of this fascinating subject, particularly with regard to phase transitions and dynamics, at an advanced tutorial level. Both general and specific aspects are considered, with competitions having several origins; differences in intrinsic interactions, interplay between intrinsic and extrinsic effects, such as geometry and disorder; irreversibility and non-equilibration. Among the specific physical application areas are supercooled liquids and glasses, high-temperature superconductors, flux or vortex pinning and motion, charge density waves, domain growth and coarsening, and electron solidification.
Download or read book Fluctuations Instabilities and Phase Transitions written by T. Riste and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the papers presented at the NATO Advanced Study Institute held at Geilo, Norway, 11th - 20th April 1975. The institute was the third in a row devoted to phase transitions. The previous two dealt with 2nd- and 1st-order transitions in equilibrium systems and the proceedings have been published.i~ In order to make an overlap wi th those institutes, the first part of this institute was devoted to 1st -or der transitions with an emphasis on the problems of metast abi l i t y and instability en countered i n spinodal decomposition, nucleation etc. The main topic was, however, that of non-equilibrium systems, and the present institute was to our knowledge the first one devoted to the physics of such systems. The discovery of the analogy between phase transitions in equilibrium systems and instabilities in non-equilibrium systems was first made by Rolf Landauer in 1961 and later independently by others. The analogy was first pointed out for electronic devices (tunnel diodes, Gunn oscillators, lasers, etc. ) and the treatment of hydrodynamic instabilities followed later.
Download or read book Pressure induced Electronic Phase Transitions in Transition Metal Oxides and Rare Earth Metals written by Brian Ross Maddox and published by . This book was released on 2006 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Phase Transitions II written by K. Alex Müller and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural Phase Transitions II, like its predecessor (Topics in Current Physics, Vol. 23), presents selected methods and recent advances in the experimental investigation of phase transitions in solids. The two chapters in this volume deal with electron paramagnetic resonance (EPR), and with nuclear magnetic and nuclear quadrupole resonance (NMR-NQR). Both techniques are particularly sensitive to local properties. The chapter on EPR concentrates largely on the investigation of static properties, including mean-field behaviour, critical and multicritical phenomena, whilst NMR is shown to be a powerful tool for studying nonlinear dynamics, incommensurate transitions, and disordered systems. This book will serve as an excellent introduction to the methodology and applications of EPR and NMR-NQR for all those wishing to become acquainted with these important tools for studying structural phase transitions.
Download or read book Reconstructive Phase Transitions written by Pierre Toldano and published by World Scientific. This book was released on 1996 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the phenomenological theory of first-order structural phase transitions, with a special emphasis on reconstructive transformations in which a group-subgroup relationship between the symmetries of the phases is absent. It starts with a unified presentation of the current approach to first-order phase transitions, using the more recent results of the Landau theory of phase transitions and of the theory of singularities. A general theory of reconstructive phase transitions is then formulated, in which the structures surrounding a transition are expressed in terms of density-waves, providing a natural definition of the transition order-parameters, and a description of the corresponding phase diagrams and relevant physical properties. The applicability of the theory is illustrated by a large number of concrete examples pertaining to the various classes of reconstructive transitions: allotropic transformations of the elements, displacive and order-disorder transformations in metals, alloys and related structures, crystal-quasicrystal transformations.
Download or read book Electronic transitions and correlation effects written by Johan Jönsson and published by Linköping University Electronic Press. This book was released on 2020-03-17 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: Macroscopic properties of real materials, such as conductivity, magneticproperties, crystal structure parameters, etc. are closely related or evendetermined by the configuration of their electrons, characterized by electronicstructure. By changing the conditions, e.g, pressure, temperature, magnetic/electric field, chemical doping, etc. one can modify the electronic structure ofsolids and therefore induce a phase transition(s) between different electronic andmagnetic states. One famous example is a Mott metal-to-insulator phase transition,at which a material undergoes a significant, often many orders of magnitude, changeof conductivity caused by the interplay between itineracy and localization of thecarriers. Electronic topological transitions (ETT) involvechanges in the topology of a metal's Fermi surface. This thesis investigates theeffect of such electronic transitions in various materials, ranging from pureelements to complex compounds. To describe the interplay between electronic transitionsand properties of real materials,different state-of-the-art computational methods are used. The densityfunctional theory(DFT), as well as the DFT + U method, is used to calculatestructural properties. The validity of recently introduced exchange-correlationfunctionals, such as the strongly constrained and appropriately normed (SCAN)functional, is also assessed for magnetic elements. In order toinclude dynamical effects of electron interactions we use the DFT + dynamical meanfield theory (DFT + DMFT) method. Experiments in hcp-Os have reported peculiarities in the ratio betweenlattice parameters at high pressure. Previous calculations have suggested these transitions maybe related to ETTs and even crossings of core levels at ultra high pressure. Inthis thesis it is shownthat the crossing of core levels is a general feature of heavy transitionmetals. Experiments have therefore been performed to look for indications ofthis transition in Ir using X-ray absorption spectroscopy. In NiO, strongrepulsion between electrons leads to a Mott insulating state at ambientconditions. It has long been predicted that high pressure will lead to aninsulator-to-metal transition. This has been suggested to be accompanied by aloss of magnetic order, and a structural phase transition. In collaboration withexperimentalists we look for thistransition by investigating the X-ray absorption spectra as well as themagnetic hyperfine field. We find no evidence of a Mott transition up to 280GPa. In the Mott insulator TiPO4, application of external pressure has beensuggested to lead to a spin-Peierls transition at room temperature. Weinvestigate the dimerisation and the magnetic structure of TiPO4 at high pressure.As pressure is increased further, TiPO4 goes through a metal to insulatortransition before an eventual crystallographic phase transition. Remarkably, thenew high pressure phases are found to be insulators; the Mott insulating stateis restored. MAX phases are layered materials that combinemetallic and ceramic properties and feature layers of M-metal and X-C or N atomsinterconnected by A-group atoms. Magnetic MAX-phases with their low dimensionalmagnetism are promising candidates for applications in e.g., spintronics.The validity of various theoretical approaches are discussed in connection tothe magnetic MAX-phase Mn2GaC. Using DFT and DFT + DMFT we consider the hightemperature paramagnetic state, and whether the magnetic moments are formed bylocalized or itinerant electrons. Ett materials makroskopiska egenskaper, såsom ledningsförmåga, magnetiska egenskaper, kristallstrukturparametrar, etc. är relaterade till, eller till och med bestämda av elektronernas konfiguration, vilken karakteriseras av elektronstrukturen. Genom att ändra förhållandena, till exempel via tryck, temperatur, magnetiska och/eller elektriska fält, dopning, etc. är det möjligt att modifiera elektronstrukturen hos ett material, och därigenom inducera fasövergångar mellan olika magnetiska och elektron-tillstånd. Mott metall-till-isolator övergången är ett berömt exempel på en fasövergång, då ett material genomgår en omfattande, ofta flera tiopotenser, förändring i ledningsförmåga, orsakad av samspelet mellan ambulerande och lokaliserade laddningsbärare. Vid en elektronisk-topologisk övergång (eng. electronic topological transition, ETT) sker förändringar i elektronernas energifördelning vilket modifierar materialets Fermi-yta. I den här avhandlingen undersöks dylika övergångar i olika material, från rena grundämnen till komplicerade föreningar. Flera olika toppmoderna beräkningsmetoder används för att redogöra för samspelet mellan elektroniska fasövergångar och egenskaper hos riktiga material. Täthetsfunktionalterori (eng. density functional theory, DFT), samt DFT + U, har används för att beräkna strukturella egenskaper. Lämplighetsgraden i att använda nyligen publicerade exchangecorrelation- funktionaler, såsom SCAN (eng. strongly constrained and appropriately normed), för att beskriva magnetiska grundämnen undersöks även. För att inkludera dynamiska elektronkorrelationer använder vi metoden DFT + dynamisk medelfältteori (eng. dynamical mean field theory, DMFT). Experiment utförda på hcp-Os vid högt tryck visar underliga hopp i kvoten mellan gitterparametrar. Tidigare beräkningar har indikerat att dessa övergångar kan vara relaterade till elektronisk-topologiska övergångar och korsande av kärntillstånd. I den här avhandlingen visas också att korsning av kärntillstånden är en generell egenskap hos tunga övergångsmetaller. Därför utförs röntgenabsorptionsexperiment på Ir för att leta efter tecken på denna typ av övergång. Övergångsmetalloxiden NiO har sedan länge förutspåtts genomgå en isolator till metall Mott-övergång. Det har föreslagits att denna övergång sker vid höga tryck i samband med att materialets magnetiska ordning försvinner och en strukturell övergång sker. I samarbete med experimentalister letar vi efter denna övergång genom att studera röntgenabsorptionsspektra och det magnetiska hyperfina fältet. Vi ser inga indikationer på en Mott-övegång, upp till ett tryck på 280 GPa. Det har föreslagits att Mott-isolatorn TiPO4 genomgår en så kallad spin-Peierls-övergång, vid rumstemperatur, när tryck appliceras. Vi undersöker dimeriseringen och den magnetiska strukturen i TiPO4 som funktion av tryck. Vid höga tryck genomgår TiPO4 ytterligare övergångar, från en isolerande till en metallisk fas för att slutligen genomgå en strukturell övergång. De nya högtrycksfaserna visar sig anmärkningsvärt vara Mott-isolatorer. MAX-faser är en grupp material med specifik kristallstruktur, som kombinerar egenskaper från keramiska material och metaller. En MAX-fas består av lager av M –metall-atomer – och X – kol- eller kväveatomer – vilka sammanbinds av atomer från grupp A. Magnetiska MAX-faser som visar magnetiska egenskaper, liknande de för lågdimensionella material, är lovande kandidater för applikation inom exempelvis spinntronik. Den här avhandlingen undersöker lämplighetsgraden i att använda diverse teoretiska metoder för att beskriva magnetiska MAX-faser. Med hjälp av DFT och DFT + DMFT undersöker vi den paramagnetiska högtemperaturfasen och huruvida de magnetiska momenten bildas av lokaliserade eller ambulerande elektroner.
Download or read book Electronic Structure and Electronic Transitions in Layered Materials written by V. Grasso and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new volume in the series Physics and Chemistry of Materials with Layered Structures satisfies the need for a comprehensive review of the progress made in the decade 1972-1982 in the field of the electronic properties of layer compounds. Some recent theoretical and experimental developments are highlighted by authori tative physicists active in current research. The previous books of this series covering similar topics are volumes 3 and 4. The present review is mainly intended to fulfill the gap up to 1982 and part of 1983. I am indebted to all the authors for their friendly co-operation and continuous effort in preparing the contributions in their own fields of competence. I am sure that both the expertise scientists and the beginners in the field of the electronic properties of layered materials will find this book a valuable tool for their research work. Warm thanks are due to Prof. E. Mooser, General Editor of the series, for his constant and authoritative advice. * * * This book has been conceived as a tribute to Prof. Franco Bassani to whom the Italian tradition in the field of layer compounds, as well as in other fields of solid state physics, owes much. The authors of this review have all benefited at some time of their professional life from close cooperation with him. Istituto di Struttura della Materia, VINCENZO GRASSO Universitd di Messina IX V Grasso (ed.). Electronic Structure and Electronic Transitions in Layered Materials. ix.
Download or read book Direct Observation of Electronic liquid crystal Phase Transitions and Their Microscopic Origin in La1 3Ca2 3MnO3 written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The ground-state electronic order in doped manganites is frequently associated with a lattice modulation, contributing to their many interesting properties. However, measuring the thermal evolution of the lattice superstructure with reciprocal-space probes alone can lead to ambiguous results with competing interpretations. Here, we provide direct observations of the evolution of the superstructure in La1/3Ca2/3MnO3 in real space, as well as reciprocal space, using transmission electron microscopic (TEM) techniques. We show that the transitions are the consequence of a proliferation of dislocations plus electronic phase separation. The resulting states are well described by the symmetries associated with electronic-liquid-crystal (ELC) phases. Furthermore, our results resolve the long-standing controversy over the origin of the incommensurate superstructure and suggest a new structural model that is consistent with recent theoretical calculations.
