NMR-MRI, muSR and Mossbauer Spectroscopies in Molecular Magnets

This book is a collection of scientific articles on the basic aspects of nuclear magnetic resonance (NMR), muon spin rotation (µSR) and M¨ossbauer spectroscopies, applied to the study of molecular magnets and to related systems, such as low-dimensional magnets and contrast agents for magnetic resonance imaging (MRI). These articles gather, to a certain extent, the lecture notes presented by the authors at the Training School on NMR-MRI, µSR and M¨ossbauer Techniques, held in Pavia from the 17th to the 30th of September 2006. The motivation for the School and for the publication of this book originates from the growing interest of a broad scientific community to the field of molecular magnetism where the aforementioned techniques play a key role. Nowadays several groups of physicists, of chemists and some groups of biologists work in this field in order to unravel the fundamental physical aspects of molecular magnets which are of interest for their future applicability as storage units, in quantum computation, in hybrid superconducting-magnetic systems or as contrast agents, for example. Nevertheless, the use and the knowledge of NMR-MRI, µSR and M¨ossbauer spectroscopies is still limited to a small scientific community. The purpose of the School and of the book was to introduce these techniques to a broader scientific community working on molecular magnets and related systems. In particular, to give the basic principles of each technique, to show which information is derived, for example, from the spectra, from the muon depolarization curves or from the relaxation rates, and how it is complementary to the one obtained by other techniques. Moreover, it will be shown how from the experimental results derived by these techniques one can tailor the properties of molecular magnets and nanoparticles which, in turn, can be used as contrast agents for MRI. The book is addressed to graduate and senior researchers working on molecular magnets or closely related areas, having a background on quantum mechanics. It is divided into three main parts, each one dedicated to a different spectroscopy. The first chapter of each part is a short tutorial introduction to each one of the spectroscopies. Since an exhaustive introduction is out of the aim of this book, reference is properly made to text books and to web sites which allow a deeper understanding of the basic principles underlaying these techniques. This introductory chapter is followed by more specialized ones giving an overview on recent results obtained by NMR, µSR and M¨ossbauer spectroscopies in molecular magnets and in strictly related areas. Two chapters of the first part are dedicated to MRI and to the investigation of contrast agents suitable for applications in MRI.