In everyday life, minute thermally-induced elongations are essentially invisible to the naked eye; but even minute expansions can fatally degrade device processing and performance in – for example – the semiconductor industry. Materials which, astonishingly, contract upon heating offer the great advantage of being able to tune the overall thermal expansion of composite materials or to act as thermal-expansion compensators. The development of these negative thermal expansion materials has advanced rapidly during the past fifteen years, and a wide variety of materials of differing types has now been identified, as well as a number of intriguing mechanisms which help to avoid the apparent inviolable tendency of size to increase with temperature. The present work is the most up-to-date summary of the current range of negative thermal expansion materials and of the associated mechanisms. Negative Thermal Expansion Materials, Thermomiotic Behavior, Thermal Stress-Fracture, Thermal Expansion of Composites, Thin-Film Design, Metamaterials

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This book discusses bulk solids that derive their mechanical properties not from those of their base materials, but from their designed microstructures. Focusing on the negative mechanical properties, it addresses topics that reveal the counter-intuitive nature of solids, specifically the negativity of properties that are commonly positive, such as negative bulk modulus, negative compressibility, negative hygroexpansion, negative thermal expansion, negative stiffness phase, and negative Poisson’s ratio. These topics are significant not only due to the curiosity they have sparked, but also because of the possibility of designing materials and structures that can behave in ways that are not normally expected in conventional solids, and as such, of materials that can outperform solids and structures made from conventional materials. The book includes illustrations to facilitate learning, and, where appropriate, reference tables. The presentation is didactic, starting with simple cases, followed by increasingly complex ones. It provides a solid foundation for graduate students, and a valuable resource for practicing materials engineers seeking to develop novel materials through the judicious design of microstructures and their corresponding mechanisms.

This book brings together more closely researchers working in the two fields of quantum optics and nano-optics and provides a general overview of the main topics of interest in applied and fundamental research. The contributions cover, for example, single-photon emitters and emitters of entangled photon pairs based on epitaxially grown semiconductor quantum dots, nitrogen vacancy centers in diamond as single-photon emitters, coupled quantum bits based on trapped ions, integrated waveguide superconducting nanowire single-photon detectors, quantum nano-plasmonics, nanosensing, quantum aspects of biophotonics and quantum metamaterials. The articles span the bridge from pedagogical introductions on the fundamental principles to the current state-of-the-art, and are authored by pioneers and leaders in the field. Numerical simulations are presented as a powerful tool to gain insight into the physical behavior of nanophotonic systems and provide a critical complement to experimental investigations and design of devices.

Ferromagnetism of metallic systems, especially those including transition metals, has been a controversial subject of modern science for a long time. This controversy sterns from the apparent dual character of the d-electrons responsible for magnetism in transition metals, i.e., they are itinerant elec trons described by band theory in their ground state, while at finite tem peratures they show various properties that have long been attributed to a system consisting of local magnetic moments. The most familiar example of these properties is the Curie-Weiss law of magnetic susceptibility obeyed by almost all ferromagnets above their Curie temperatures. At first the problem seemed to be centered around whether the d-elec trons themselves are localized or itinerant. This question was settled in the 1950s and early 1960s by various experimental investigations, in particular by observations of d-electron Fermi surfaces in ferromagnetic transition metals. These observations are generally consistent with the results of band calculations. Theoretical investigations since then have concentrated on explaining this dual character of d-electron systems, taking account of the effects of electron-electron correlations in the itinerant electron model. The problem in physical terms is to study the spin density fluctuati·ons, which are ne glected in the mean-field or one-electron theory, and their influence on the physical properties.