Structural Phase Transitions in Layered Transition Metal Compounds - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Structural Phase Transitions in Layered Transition Metal Compounds write by K. Motizuki. This book was released on 2012-12-06. Structural Phase Transitions in Layered Transition Metal Compounds available in PDF, EPUB and Kindle. 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.
Structural Phase Transitions in Layered Transition Metal Compounds
Structural Phase Transitions in Layered Transition Metal Compounds - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Structural Phase Transitions in Layered Transition Metal Compounds write by K Motizuki. This book was released on 1986-10-31. Structural Phase Transitions in Layered Transition Metal Compounds available in PDF, EPUB and Kindle.
Magnetic Properties of Layered Transition Metal Compounds
Magnetic Properties of Layered Transition Metal Compounds - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Magnetic Properties of Layered Transition Metal Compounds write by L.J. de Jongh. This book was released on 2012-12-06. Magnetic Properties of Layered Transition Metal Compounds available in PDF, EPUB and Kindle. 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.
Phase Transitions in Low-Dimensional Transition Metal Compounds
Phase Transitions in Low-Dimensional Transition Metal Compounds - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Phase Transitions in Low-Dimensional Transition Metal Compounds write by . This book was released on 2006. Phase Transitions in Low-Dimensional Transition Metal Compounds available in PDF, EPUB and Kindle. The materials in the scope of this dissertation belong to the domain where Peierls and Mott physics meet - in other words, both electron-phonon coupling and electronic correlations play an essential role in these systems. With 1T-TaSe2 a layered transition metal compound was investigated that can be regarded as a paradigm quasi-two-dimensional charge density wave (CDW) system. The appeal of this material certainly lies in the occurrence of a surface Mott metal-insulator transition, which is driven by CDW-induced changes of the electronic bandwidth and can thus be controlled simply by varying the temperature. In this thesis, a detailed examination of the electronic structure in the presence of the CDW is presented. The results of DFT calculations make it possible to identify a separated conduction band with a strongly reduced width compared to the undistorted state, which explains the rather unusual appearance of Mott physics in a 5d transition metal compound. This observation corroborates the Mott-Hubbard scenario with star-of-David clusters as relevant sites of the corresponding Hubbard picture. On the experimental side, clear evidence for the Mott transition at the surface of 1T-TaSe2 is given in form of angle-resolved photoemission data. This represents one of the few examples where one is able to observe the evolution of the spectral function while going through the transition by tuning the crucial ration U/W within the same single crystal. Compared to the charge-Peierls transition, its counterpart involving the spin degree of freedom - i.e., the spin-Peierls transition - must be considered a much rarer phenomenon. The compounds TiOCl and TiOBr studied in the course of this dissertation are, together with CuGeO3, the only known inorganic materials to exhibit this instability. In this thesis x-ray diffraction experiments provide direct evidence for the spin-Peierls nature of TiOCl, thus leading to a coherent spin-Peierls picture of the oxyhalides with two success.
Emergent States in Photoinduced Charge-Density-Wave Transitions
Emergent States in Photoinduced Charge-Density-Wave Transitions - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Emergent States in Photoinduced Charge-Density-Wave Transitions write by Alfred Zong. This book was released on 2021-09-17. Emergent States in Photoinduced Charge-Density-Wave Transitions available in PDF, EPUB and Kindle. 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.
