Magnetic Resonance of Phase Transitions shows how the effects of phase transitions are manifested in the magnetic resonance data. The book discusses the basic concepts of structural phase and magnetic resonance; various types of magnetic resonances and their underlying principles; and the radiofrequency methods of nuclear magnetic resonance. The text also describes quadrupole methods; the microwave technique of electron spin resonance; and the Mössbauer effect. Phase transitions in various systems such as fluids, liquid crystals, and crystals, including paramagnets and ferroelectrics, are also considered. Physicists and scientists working in energetic materials laboratories will find the book invaluable.
Structural Phase Transitions II, like its predecessor (Topics in Current Physics, Vol. 23), presents selected methods and recent advances in the experimental investigation of phase transitions in solids. The two chapters in this volume deal with electron paramagnetic resonance (EPR), and with nuclear magnetic and nuclear quadrupole resonance (NMR-NQR). Both techniques are particularly sensitive to local properties. The chapter on EPR concentrates largely on the investigation of static properties, including mean-field behaviour, critical and multicritical phenomena, whilst NMR is shown to be a powerful tool for studying nonlinear dynamics, incommensurate transitions, and disordered systems. This book will serve as an excellent introduction to the methodology and applications of EPR and NMR-NQR for all those wishing to become acquainted with these important tools for studying structural phase transitions.
Phase transitions in which crystalline solids undergo structural changes present an interesting problem in the interplay between the crystal structure and the ordering process. This text, intended for readers with some prior knowledge of condensed-matter physics, emphasizes the basic physics behind such spontaneous structural changes in crystals. Starting with the relevant thermodynamic principles, the book discusses the nature of order variables and their collective motion in a crystal lattice; in a structural phase transition a singularity in such a collective mode is responsible for the lattice instability, as revealed by soft phonons. This mechanism is analogous to the interplay of a charge-density wave and a periodically deformed lattice in low-dimensional conductors. The text also describes experimental methods for modulated crystal structures and gives examples of structural changes in representative systems. The book is divided into two parts. The first, theoretical, part includes such topics as: the Landau theory of phase transitions; statistics, correlations and the mean-field approximation; pseudospins and their collective modes; soft lattice modes and pseudospin condensates; lattice imperfections and their role in the phase transitions of real crystals. The second part discusses experimental studies of modulated crystals using x-ray diffraction, neutron inelastic scattering, light scattering, dielectric measurements, and magnetic resonance spectroscopy.
The Advanced Study Institute on Phase Transitions in Surface Films was held at the Ettore Majorana Centre for Scientific Cul ture in Erice, Sicily, during June 11 to June 25, 1979. This Institute was the second course of the International School of Low Temperature Physics which was established at the Centre in 1977, with the guidance and inspiration of T. Regge and A. Zichichi. The 1979 course selected a topic on one of the most rapidly advancing fields of condensed matter physics in the late 70's. The program of topics and speakers was developed with the advice of the Organizing Committee, composed of J. Friedel, N. D. Mermin, R. E. Peierls, T. Regge and J. Wheatley. These two weeks were memorable for the range and depth of the lectures and seminars, and the sustained high interest of the students and faculty through a damanding schedule of over 5 hours a day of formal sessions. A large fraction of the leading researchers in the field were there. It would have been impossible to gather such a large group five years earlier, for the field itself is hardly 10 years old. Although the foundations of the thermodynamics of surface films were laid down by Gibbs about 100 years ago, and experiments on oil/water monolayers were carried out by Pockels and Rayleigh at about the same time, the beginnings of the modern field were much more recent.
Intended for readers with some prior knowledge of condensed-matter physics, this text emphasises the basic physics behind spontaneous structural changes in crystals. Starting with the relevant thermodynamic principles, the author discusses the nature of order variables and their collective motion in a crystal lattice. He also goes on to describe experimental methods for modulated crystal structures and gives examples of structural changes in representative systems. Both a graduate text and reference work.
This important and timely book deals with the theoretical and experimental investigation of the phase transitions which occur in complex fluid systems, namely lyotropic systems, microemulsions, colloids, gels, polymers, biological membranes, Langmuir monolayers, and ferrofluids. It contains 20-odd review papers from the major contributors to this rapidly growing field of research, summarizing the main results obtained in the description and understanding of the phase transitions taking place between the isotopic, nematic, cholesteric, lamellar, hexagonal, and cubic mesophases of complex fluids.
Research on ferroelectricity and ferroelectric materials started in 1920 with the discovery by Valasek that the variation of spontaneous polarization in Rochelle salt with sign and magnitude of an applied electric field traced a complete and reproducible hysteresis loop. Activity in the field was sporadic until 1935, when Busch and co-workers announced the observation of similar behavior in potassium dihydrogen phosphate and related compounds. Progress thereafter continued at a modest level with the undertaking of some theoretical as well as further experimental studies. In 1944, von Hippel and co-workers discovered ferroelectricity in barium titanate. The technological importance of ceramic barium titanate and other perovskites led to an upsurge of interest, with many new ferroelectrics being identified in the following decade. By 1967, about 2000 papers on various aspects of ferroelectricity had been published. The bulk of this widely dispersed literature was concerned with the experimental measurement of dielectric, crystallographic, thermal, electromechanical, elastic, optical, and magnetic properties. A critical and excellently organized cpmpilation based on these data appeared in 1969 with the publica tion of Landolt-Bornstein, Volume 111/3. This superb tabulation gave instant access to the results in the literature on nearly 450 pure substances and solid solutions of ferroelectric and antiferroelectric materials. Continuing interest in ferroelectrics, spurred by the growing importance of electrooptic crystals, resulted in the publication of almost as many additional papers by the end of 1969 as had been surveyed in Landolt-Bornstein.
Nuclear magnetic resonance imaging is one of several new experimental tech niques which have rec{ ,tly been applied to food systems. NMR in general and nuclear magnetic resonance imaging are powerful probes of the microscopic and macroscopic changes occurring in foods during processing, storage and utilization. The training that food scientists and food engineers have received in the past has often omitted specific courses in physical chemistry that form the theoretical and practical foundation necessary to fully utilized magnetic resonance experimental techniques. The goal of Magnetic Resonance Imaging in Foods is to introduce food scien tists and food engineers to magnetic resonance imaging and provide a basis for further study. As such the book begins with two chapters of an introductory nature. The first chapter introduces magnetic resonance phenomena, NMR in general, and MRI in detail. Particular emphasis is given to the limitations and typical ranges available for studying particular phenomena, for example, the range of diffusivities that can be studied using commercial grade NMR equipment. Chapter 2 gives a brief introduction to the classical physical model of NMR first introduced by Felix Bloch in 1946 and aspects important to the interpretation of MRI data. This chapter is provided for the researchers and students interested in more details of the basic theory. Chapter 2 can be skipped by those individuals not requiring more information on the basic theory of NMR. The next several chapters of the book are on applications of MRI to food systems.
