Rudolph Mossbauer discovered the phenomenon of recoil-free nuclear resonance fluorescence in 1957-58 and the first indications of hyperfine interactions in a chemical compound were obtained by Kistner and Sunyar in 1960. From these beginnings the technique of Mossbauer spectroscopy rapidly emerged and the astonishing versatility of this new technique soon led to its extensive application to a wide variety of chemical and solid-state problems. This book reviews the results obtained by Mossbauer spectroscopy during the past ten years in the belief that this will provide a firm basis for the continued development and application of the technique to new problems in the future. It has been our aim to write a unified and consistent treatment which firstly presents the basic principles underlying the phenomena involved, then outlines the experimental techniques used, and finally summarises the wealth of experimental and theoretical results which have been obtained. We have tried to give some feeling for the physical basis of the Mossbauer effect with out extensive use of mathematical formalism, and some appreciation of the experimental methods employed without embarking on a detailed discussion of electronics and instrumentation. However, full references to the original literature are provided and particular points can readily be pursued in more detail if required.

This volume deals with the interaction between moments of excited or radioactive nuclei and electromagnetic fields. The experimental techniques developed for the observation of this hyperfine interaction are governed by the lifetime of the nuc lear states in question. The dynamics of the interaction are reflected by the time dependence of the spatial distribution of the radioactive decay radiation. Basically, the experiments yield information on the energy shifts and/or splittings of the nuc lear levels. These quantities are determined essentially by the product of the nuc lear moment and the electromagnetic field acting at the site of the nucleus. Due to the strong decrease in the fields with distance, the measurements probe these fields within a highly localized region centered around the radioactive nuclei. Detailed experimental methods with numerous ramifications were developed in the early sixties. In the period which followed, the main emphasis was on excitation of short-lived nuclear states by means of pulsed particle accelerators, implantation of radioactive nuclei, and production of polarized a-unstable nuclei by nuclear re actions with polarized neutrons or particles. The seventies were a period of fruit ful applications directed to extensive studies of the moments of excited nuclear states on the one hand, and local internal fields on the other, resulting in far reaching information on atomic and solid-state properties. The organization of this Topics volume follows these main lines of research.

This book emphasizes the importance of the fascinating atomistic insights into the defects and the impurities as well as the dynamic behaviors in silicon materials, which have become more directly accessible over the past 20 years. Such progress has been made possible by newly developed experimental methods, first principle theories, and computer simulation techniques. The book is aimed at young researchers, scientists, and technicians in related industries. The main purposes are to provide readers with 1) the basic physics behind defects in silicon materials, 2) the atomistic modeling as well as the characterization techniques related to defects and impurities in silicon materials, and 3) an overview of the wide range of the research fields involved.

This is the sixth volume of a series that provides a continuing forum for publication of developments in M6ssbauer effect method ology and of spectroscopy and its applications. M ossbauer Effect Methodology, Volume 6, records the proceedings of the Sixth Symposium on M6ssbauer Effect Methodology. The symposium was sponsored by the New England Nuclear Corporation and concentrated on methodology, applications, and spectroscopy, with special sections on lunar sample work and on standardization and nomenclature. The symposium was held at the Palmer House in Chicago on January 25, 1970. Dr. J. C. Walker presided over the after noon and evening sessions. About two hundred participants attended, reflecting the continued importance of and interest in this series. Austin Science Associates, Elron Electronic Industries, High Voltage Engineering Corporation, and Reuter-Stokes Electronic Components Company demonstrated lines of equipment for M6ssbauer work. The usual high degree of interest in the well-designed commercial instrumentation was evident. The highlight of the symposium was the session on lunar samples. Fortuitously, the timing of the symposium permitted it to provide one ofthe earliest exposures ofthe lunar results to the scientific community. Many papers on other applications were presented, including work on frozen aqueous solutions. Four papers on methodology development made up one session, including reports on a polarized source, on a coincidence technique, and on the use of radio frequency to perturb hyperfine levels. As usual, many of the papers report work in fields remote from basic physics.