The ancient Greeks believed that all matter was composed of four elements: earth, water, air, and fire. By a remarkable coincidence (or perhaps not), today we know that there are four states of matter: solids (e.g. earth), liquids (e.g. water), gasses (e.g. air) and plasma (e.g. ionized gas produced by fire). The plasma state is beyond the scope of this book and we will only look at the first three states. Although on the microscopic level all matter is made from atoms or molecules, everyday experience tells us that the three states have very different properties. The aim of this book is to examine some of these properties and the underlying physics.

The minimum temperature in the natural universe is 2.7 K. Laboratory refrigerators can reach temperatures in the microkelvin range. Modern industrial refrigerators cool foods at 200 K, whereas space mission payloads must be capable of working at temperatures as low as 20 K. Superconducting magnets used for NMR work at 4.2 K. Hence the properties of materials must be accurately known also at cryogenic temperatures. This book provides a guide for engineers, physicists, chemists, technicians who wish to approach the field of low-temperature material properties. The focus is on the thermal properties and a large spectrum of experimental cases is reported. The book presents updated tables of low-temperature data on materials and a thorough bibliography supplements any further research. Key Features include: ° Detailed technical description of experiments ° Description of the newest cryogenic apparatus ° Offers data on cryogenic properties of the latest new materials ° Current reference review

that about 100 journals are required to yield fifty In 1957, the Thermophysical Properties Research percent. But that other fifty percent! It is scattered Center (TPRC) of Purdue University, under the leadership of its founder, Professor Y. S. Touloukian, through more than 3500 journals and other docu began to develop a coordinated experimental, ments, often items not readily identifiable or ob tainable. Over 85,000 references are now in the theoretical, and literature review program covering a set of properties of great importance to science and files. technology. Over the years, this program has grown Thus, the man who wants to use existing data, rather than make new measurements himself, faces steadily, producing bibliographies, data compila a long and costly task if he wants to assure himself tions and recommendations, experimental measure ments, and other output. The series of volumes for that he has found all the relevant results. More often which these remarks constitute a foreword is one of than not, a search for data stops after one or two results are found-or after the searcher decides he these many important products. These volumes are a monumental accomplishment in themselves, re has spent enough time looking. Now with the quiring for their production the combined knowledge appearance of these volumes, the scientist or engineer and skills of dozens of dedicated specialists. The who needs these kinds of data can consider himself very fortunate.

It has been almost thirty years since the publication of a book that is entirely dedicated to the theory, description, characterization and measurement of the thermal conductivity of solids. The recent discovery of new materials which possess more complex crystal structures and thus more complicated phonon scattering mechanisms have brought innovative challenges to the theory and experimental understanding of these new materials. With the development of new and novel solid materials and new measurement techniques, this book will serve as a current and extensive resource to the next generation researchers in the field of thermal conductivity. This book is a valuable resource for research groups and special topics courses (8-10 students), for 1st or 2nd year graduate level courses in Thermal Properties of Solids, special topics courses in Thermal Conductivity, Superconductors and Magnetic Materials, and to researchers in Thermoelectrics, Thermal Barrier Materials and Solid State Physics.