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The investigation of the interfacial phase transitions in fluid systems with short-range intermetallic interactions are of great interest. The phenomena were studied in two systems exhibiting a liquid-liquid miscibility gap: at the fluid/wall interface in fluid KxKCl1-x and at the fluid/vacuum interface of the Ga1 xBix alloys. To characterize the interfacial changes of the ultra thin films (composition, thickness and their evolution with time) the spectroscopic ellipsometry was performed over a wide spectral range. Whereas in the experiments on KxKCl1-x an existing ellipsometer could be used, a completely new UHV-apparatus including the in-situ phase modulation ellipsometer had to be developed for Ga1 xBix alloys. For the KxKCl1-x system new results on complete wetting at solid-liquid coexistence as well as in the homogenous liquid phase (prewetting) are presented. The spectra show the typical F center absorption which indicates that the film is a salt-rich phase. The thickness strongly increases approaching the monotectic from 30 to 440 nm, which is in agreement with the tetra point wetting scenario. For this interpretation a quantitative description of the excess Gibbs energy has been developed. For the Ga1 xBix system the results on complete wetting, surface freezing and oscillatory interfacial instabilities are presented. The high-precision spectra have been recorded approaching the liquid-liquid miscibility. These spectra have been modeled using a Ga-Bi effective medium approximation for the substrate covered by a film of liquid Bi. The measurements give evidence of tetra point wetting in the Ga-Bi system. First ellipsometric study of the surface freezing in Ga-Bi has been performed. Within the miscibility gap a very interesting effect of surface and bulk oscillatory instability was observed. The details of this process at present are not well understood, but a qualitative description is given.
molten salt --- surface phase transition --- spectroscopic ellipsometry --- Ga-Bi alloys
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This book provides information on thermal energy storage systems incorporating phase change materials (PCMs) which are widely preferred owing to their immense energy storage capacity. The thermal energy storage (TES) potential of PCMs has been deeply explored for a wide range of applications, including solar/electrothermal energy storage, waste heat storage, and utilization, building energy-saving, and thermal regulations. The inherent shortcomings like leakage during phase transition and poor thermal conductivity hamper their extensive usage. Nevertheless, it has been addressed by their shape stabilization with porous materials and dispersing highly conductive nanoparticles. Nanoparticles suspended in traditional phase change materials enhance the thermal conductivity. The addition of these nanoparticles to the conventional PCM enhances the storage. In this book, the history of Nano Enhanced Phase Change Materials (NEPCM), preparation techniques, properties, theoretical modeling and correlations, and the effect of all these factors on the potential applications such as: solar energy, electronics cooling, heat exchangers, building, battery thermal management, thermal energy storage are discussed in detail. Future challenges and future work scope have been included. The information from this book can enable the readers to come up with novel techniques, resolve existing research limitations, and come up with novel NEPCM, that can be implemented for various applications.
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This book comprehensively presents an unconventional quantum criticality caused by valence fluctuations, which offers theoretical understanding of unconventional Fermi-liquid properties in cerium- and ytterbium-based heavy fermion metals including CeCu2(Si,Ge)2 and CeRhIn5 under pressure, and quasicrystal β-YbAlB4 and Yb15Al34Au51. The book begins with an introduction to fundamental concepts for heavy fermion systems, valence fluctuation, and quantum phase transition, including self-consistent renormalization group theory. A subsequent chapter is devoted to a comprehensive description of the theory of the unconventional quantum criticality based on a valence transition, featuring explicit temperature dependence of various physical quantities, which allows for comparisons to relevant experiments. Lastly, it discusses how ubiquitous the valence fluctuation is, presenting candidate materials not only in heavy fermions, but also in strongly correlated electrons represented by high-Tc superconductor cuprates. Introductory chapters provide useful materials for learning fundamentals of heavy fermion systems and their theory. Further, experimental topics relevant to valence fluctuations are valuable resources for those who are new to the field to easily catch up with experimental background and facts.
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Aggregation (Chemistry) --- Clustering of particles --- Particles --- Precipitation (Chemistry) --- Clustering --- chemistry --- biology --- materials science --- aggregates --- aggregation --- Chemical Precipitation --- Precipitation, Chemical --- Phase Transition
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This book provides information on thermal energy storage systems incorporating phase change materials (PCMs) which are widely preferred owing to their immense energy storage capacity. The thermal energy storage (TES) potential of PCMs has been deeply explored for a wide range of applications, including solar/electrothermal energy storage, waste heat storage, and utilization, building energy-saving, and thermal regulations. The inherent shortcomings like leakage during phase transition and poor thermal conductivity hamper their extensive usage. Nevertheless, it has been addressed by their shape stabilization with porous materials and dispersing highly conductive nanoparticles. Nanoparticles suspended in traditional phase change materials enhance the thermal conductivity. The addition of these nanoparticles to the conventional PCM enhances the storage. In this book, the history of Nano Enhanced Phase Change Materials (NEPCM), preparation techniques, properties, theoretical modeling and correlations, and the effect of all these factors on the potential applications such as: solar energy, electronics cooling, heat exchangers, building, battery thermal management, thermal energy storage are discussed in detail. Future challenges and future work scope have been included. The information from this book can enable the readers to come up with novel techniques, resolve existing research limitations, and come up with novel NEPCM, that can be implemented for various applications.
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This thesis describes key contributions to the fundamental understanding of materials structure and dynamics from a microscopic perspective. In particular, the thesis reports several advancements in time-domain methodologies using ultrafast pulses from X-ray free-electron lasers (FEL) to probe the interactions between electrons and phonons in photoexcited materials. Using femtosecond time-resolved X-ray diffraction, the author quantifies the coherent atomic motion trajectory upon sudden excitation of carriers in SnSe. This allows the reconstruction of the nonequilibrium lattice structure and identification of a novel lattice instability towards a higher-symmetry structure not found in equilibrium. This is followed by an investigation of the excited-state phonon dispersion in SnSe using time-resolved X-ray diffuse scattering which enables important insight into how photoexcitation alters the strength of specific bonds leading to the novel lattice instability observed in X-ray diffraction. Finally, by combining ultrafast X-ray diffraction and ARPES, the author performs quantitative measurements of electron-phonon coupling in Bi2Te3 and Bi2Se3. The findings highlight the importance of time-resolved X-ray scattering techniques based on FELs, which reveals the details of interplay between electron orbitals, atomic bonds, and structural instabilities. The microscopic information of electron phonon interaction obtained from these methods can rationalize ways to control materials and to design their functional properties.
Lasers. --- Optical spectroscopy. --- Condensed matter. --- Solid state physics. --- Laser. --- Laser-Matter Interaction. --- Optical Spectroscopy. --- Structure of Condensed Matter. --- Electronic Devices. --- Phase Transition and Critical Phenomena.
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This book proposes a completely unique reaction kinetics theory based on the uncertainty principle of quantum mechanics; the physical viewpoint and mathematical details for the theory construction are explained, and abundant applications of the theory mainly in materials science are described. The theory argues that physical systems on reaction are in a quantum-mechanically uncertain state, and that such systems will transition to new states after a finite duration time. Based on this theory, if the magnitude of the energy uncertainty, i.e., energy fluctuation of the system on reaction can be determined, we can calculate the reaction rates not only for the thermal activation processes but also for the non-thermal activation process such as mechanical, optical, electromagnetic, or other actions. Therefore, researchers or engineers who are involved in fields such as the discovery of new chemical substances, development of materials, innovation of manufacturing processes, and also everyone purely interested in kinetic methodology find this book very stimulating and motivating. .
Chemical kinetics. --- Quantum chemistry. --- Condensed matter. --- Metals. --- Quantum physics. --- Reaction Kinetics. --- Quantum Chemistry. --- Phase Transition and Critical Phenomena. --- Metals and Alloys. --- Quantum Physics. --- Chemistry, Physical And Theoretical --- Condensed Matter --- Materials --- Quantum Theory --- Science --- Technology & Engineering
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Publishes scientific articles related to the structural science of compounds and materials in the widest sense. Knowledge of the arrangements of atoms, including their temporal variations and dependencies on temperature and pressure, is often the key to understanding physical and chemical phenomena and is crucial for the design of new materials and supramolecular devices.
Crystallization --- Crystallography --- Chemical structure --- Chemical structure. --- Crystallization. --- Crystallography. --- Leptology --- Structure, Chemical --- Crystallographies --- Crystal Growth --- Polymorphic Crystals --- Crystalline Polymorphs --- Polymorphism, Crystallization --- Crystal, Polymorphic --- Crystalline Polymorph --- Crystallization Polymorphism --- Crystallization Polymorphisms --- Crystals, Polymorphic --- Growth, Crystal --- Polymorph, Crystalline --- Polymorphic Crystal --- Polymorphisms, Crystallization --- Polymorphs, Crystalline --- Physical sciences --- Mineralogy --- Chemistry --- Chemistry, Physical and theoretical --- Separation (Technology) --- Matter --- Transition Temperature --- Phase Transition --- Constitution
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Crystallization --- Crystallography --- Chemical structure --- Chemical structure. --- Crystallization. --- Crystallography. --- Crystallographies --- Crystal Growth --- Polymorphic Crystals --- Crystalline Polymorphs --- Polymorphism, Crystallization --- Crystal, Polymorphic --- Crystalline Polymorph --- Crystallization Polymorphism --- Crystallization Polymorphisms --- Crystals, Polymorphic --- Growth, Crystal --- Polymorph, Crystalline --- Polymorphic Crystal --- Polymorphisms, Crystallization --- Polymorphs, Crystalline --- Leptology --- Structure, Chemical --- Chemistry --- Chemistry, Physical and theoretical --- Separation (Technology) --- Transition Temperature --- Phase Transition --- Physical sciences --- Mineralogy --- Matter --- Constitution
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Probabilities. --- Phase transformations (Statistical physics) --- Measure theory. --- Lebesgue measure --- Measurable sets --- Measure of a set --- Algebraic topology --- Integrals, Generalized --- Measure algebras --- Rings (Algebra) --- Phase changes (Statistical physics) --- Phase transitions (Statistical physics) --- Phase rule and equilibrium --- Statistical physics --- Probability --- Statistical inference --- Combinations --- Mathematics --- Chance --- Least squares --- Mathematical statistics --- Risk --- Gaussian Fields. --- Gibbs Measures. --- Markov Chains. --- Phase Transition. --- Statistical Mechanics.
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