Structural Phase Transitions In Layered Transition Metal Compounds

Download or read book Structural Phase Transitions in Layered Transition Metal Compounds written by K. Motizuki and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: The structural phase transition is one of the most fundamental problems in solid state physics. Layered transition-metal dichalcogenides provide us with a most exciting area for the study of structural phase transitions that are associated with the charge density wave (CDW). A large variety of structural phase transitions, such as commensurate and incommensurate transitions, and the physical proper ties related to the formation of a CDW, have been an object of intense study made for many years by methods employing modem microscopic techniques. Rather recently, efforts have been devoted to the theoretical understanding of these experimental results. Thus, McMillan, for example, has developed an elegant phenomenological theory on the basis of the Landau free energy expansion. An extension of McMillan's theory has provided a successful understanding of the successive phase transitions observed in the IT- and 2H-compounds. In addition, a microscopic theory of lattice instability, lattice dynamics, and lattice distortion in the CDW state of the transition-metal dichalcogenides has been developed based on their electronic structures. As a result, the driving force of the CDW formation in the IT- and 2H-compounds has become clear. Furthermore, the effect of lattice fluctuations on the CDW transition and on the anomalous behavior of various physical properties has been made clear microscopically.

Download or read book Structural Phase Transitions in Layered Transition Metal Compounds written by K Motizuki and published by . This book was released on 1986-10-31 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Magnetic Properties of Layered Transition Metal Compounds written by L.J. de Jongh and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last two decades low-dimensional (low-d) physics has matured into a major branch of science. Quite generally we may define a system with restricted dimensionality d as an object that is infinite only in one or two spatial directions (d = 1 and 2). Such a definition comprises isolated single chains or layers, but also fibres and thin layers (films) of varying but finite thickness. Clearly, a multitude of physical phenomena, notably in solid state physics, fall into these categories. As examples, we may mention: • Magnetic chains or layers (thin-film technology). • Metallic films (homogeneous or heterogeneous, crystalline, amorphous or microcristalline, etc.). • I-d or 2-d conductors and superconductors. • Intercalated systems. • 2-d electron gases (electrons on helium, semiconductor interfaces). • Surface layer problems (2-d melting of monolayers of noble gases on a substrate, surface problems in general). • Superfluid films of ~He or 'He. • Polymer physics. • Organic and inorganic chain conductors, superionic conductors. • I-d or 2-d molecular crystals and liquid crystals. • I-d or 2-d ferro- and antiferro electrics.

Download or read book Emergent States in Photoinduced Charge-Density-Wave Transitions written by Alfred Zong and published by Springer Nature. This book was released on 2021-09-17 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book advances understanding of light-induced phase transitions and nonequilibrium orders that occur in a broken-symmetry system. Upon excitation with an intense laser pulse, materials can undergo a nonthermal transition through pathways different from those in equilibrium. The mechanism underlying these photoinduced phase transitions has long been researched, but many details in this ultrafast, non-adiabatic regime still remain to be clarified. The work in this book reveals new insights into this phenomena via investigation of photoinduced melting and recovery of charge density waves (CDWs). Using several time-resolved diffraction and spectroscopic techniques, the author shows that the light-induced melting of a CDW is characterized by dynamical slowing-down, while the restoration of the symmetry-breaking order features two distinct timescales: A fast recovery of the CDW amplitude is followed by a slower re-establishment of phase coherence, the latter of which is dictated by the presence of topological defects in the CDW. Furthermore, after the suppression of the original CDW by photoexcitation, a different, competing CDW transiently emerges, illustrating how a hidden order in equilibrium can be unleashed by a laser pulse. These insights into CDW systems may be carried over to other broken-symmetry states, such as superconductivity and magnetic ordering, bringing us one step closer towards manipulating phases of matter using a laser pulse.

Download or read book Two-Dimensional Transition-Metal Dichalcogenides written by Alexander V. Kolobov and published by Springer. This book was released on 2016-07-26 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes the current status of theoretical and experimental progress in 2 dimensional graphene-like monolayers and few-layers of transition metal dichalcogenides (TMDCs). Semiconducting monolayer TMDCs, due to the presence of a direct gap, significantly extend the potential of low-dimensional nanomaterials for applications in nanoelectronics and nano-optoelectronics as well as flexible nano-electronics with unprecedented possibilities to control the gap by external stimuli. Strong quantum confinement results in extremely high exciton binding energies which forms an interesting platform for both fundamental studies and device applications. Breaking of spatial inversion symmetry in monolayers results in strong spin-valley coupling potentially leading to their use in valleytronics. Starting with the basic chemistry of transition metals, the reader is introduced to the rich field of transition metal dichalcogenides. After a chapter on three dimensional crystals and a description of top-down and bottom-up fabrication methods of few-layer and single layer structures, the fascinating world of two-dimensional TMDCs structures is presented with their unique atomic, electronic, and magnetic properties. The book covers in detail particular features associated with decreased dimensionality such as stability and phase-transitions in monolayers, the appearance of a direct gap, large binding energy of 2D excitons and trions and their dynamics, Raman scattering associated with decreased dimensionality, extraordinarily strong light-matter interaction, layer-dependent photoluminescence properties, new physics associated with the destruction of the spatial inversion symmetry of the bulk phase, spin-orbit and spin-valley couplings. The book concludes with chapters on engineered heterostructures and device applications such as a monolayer MoS2 transistor. Considering the explosive interest in physics and applications of two-dimensional materials, this book is a valuable source of information for material scientists and engineers working in the field as well as for the graduate students majoring in materials science.

Download or read book Physics of New Materials written by Francisco E. Fujita and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physics of New Materials After the discoveries and applications of superconductors, new ceramics, amorphous and nano-materials, shape memory and other intelligent materials, physics became more and more important, comparable with chemistry, in the research and development of advanced materials. In this book, several important fields of physics-oriented new-materials research and physical means of analyses are selected and their fundamental principles and methods are described in a simple and understandable way. It is suitable as a textbook for university materials science courses.

Download or read book Recent Advances In Magnetism Of Transition Metal Compounds: Festschrift In Honour Of Professor K Motizuki written by Akio Kotani and published by World Scientific. This book was released on 1993-03-18 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a Festschrift in honour of Professor Kazuko Motizuki on the occasion of her retirement from Osaka University. She has been active in a variety of branches of solid state physics and, in particular, has made an important contribution to the theory of magnetism. The book reviews recent advances in magnetism of transition metal compounds, both for itinerant electron systems and localized spin systems. For the former systems, band calculational methods, correlation effects, and theoretical aspects of photoemission spectroscopy are reviewed generally, and then recent progress in the theoretical and experimental understanding of magnetic properties of various kinds of intermetallic compounds and intercalation compounds of transition-metal dichalcogenides are reviewed in detail. For the latter systems, attention is focused on quantum effects, frustration and competing interaction in low-dimensional systems. Main subjects treated in the book are Haldane gap-systems, singlet-ground-state systems, triangular spin systems, and quantum spin chains with competing interactions.