Studies in Chemical Physics – serie

The emergence of M6ssbauer spectroscopy as an important experi­ mental technique for the study of solids has resulted in a wide range of applications in chemistry, physics, metallurgy and biophysics. This book is intended to summarize the elementary principles of the technique at a level appropriate to the advanced student or experienced chemist requiring a moderately comprehensive but basically non-mathematical introduction. Thus the major part of the book is concerned with the practical applications of Mossbauer spectroscopy, using carefully selected examples to illustrate the concepts. The references cited and the bibliography are intended to provide a bridge to the main literature for those who subseouent­ ly require a deeper knowledge. The text is complementary to the longer research monograph, 'Mossbauer Spectroscopy', which was written a few years ago in co-authorship with Professor N.N. Greenwood, and to whom I am deeply indebted for reading the preliminary draft of the present volume. I also wish to thank my many colleagues over the past ten years, and in particular Dr. R. Greatrex, for the many stimu­ lating discussions which we have had together. However my greatest debt is to my wife, who not only had to tolerate my eccen­ tricities during the gestation period, but being a chemist herself was also able to provide much useful criticism of the penultirna te draft.

The emergence of Mossbauer spectroscopy as an important experi­ mental technique for the study of solids has resulted in a wide range of applications in chemistry, physics, metallurgy and biophysics. This book is intended to summarize the elementary principles of the technique at a level appropriate to the advanced student or experienced chemist requiring a moderately comprehensive but basically non-mathematical introduction. Thus the major part of the book is concerned with the practical applications of Mossbauer spectroscopy, using carefully selected examples to illustrate the concepts. The references cited and the bibliography are intended to provide a bridge to the main literature for those who subseouent­ ly require a deeper knowledge. The text is complementary to the longer research monograph, 'Mossbauer Spectroscopy', which was written a few years ago in co-authorship with Professor N.N. Greenwood, and to whom I am deeply indebted for reading the preliminary draft of the present volume. I also wish to thank my many colleagues over the past ten years, and in particular Dr. R. Greatrex, for the many stimu­ lating discussions which we have had together. However my greatest debt is to my wife, who not only had to tolerate my eccen­ tricities during the gestation period, but being a chemist herself was also able to provide much useful criticism of the penultima te draft.

This book is primarily intended for graduate chemists and chemical physicists. Indeed, it is based on a graduate course that I give in the Chemistry Depart­ ment of Southampton University. Nowadays undergraduate chemistry courses usually include an introduction to quantum mechanics with particular reference to molecular properties and there are a number of excellent textbooks aimed specifically at undergraduate chemists. In valence theory and molecular spectroscopy physical concepts are often encountered that are normally taken on trust. For example, electron spin and the anomalous magnetic moment of the electron are usually accepted as postulates, although they are well understood by physicists. In addition, the advent of new techniques has led to experimental situations that can only be accounted for adequately by relatively sophisticated physical theory. Relativis­ tic corrections to molecular orbital energies are needed to explain X-ray photo­ electron spectra, while the use oflasers can give rise to multiphoton transitions, which are not easy to understand using the classical theory of radiation. Of course, the relevant equations may be extracted from the literature, but, if the underlying physics is not understood, this is a practice that is at best dissatisfy­ ing and at worst dangerous. One instance where great care must be taken is in the use of spectroscopically determined parameters to test the accuracy of elec­ tronic wave functions.