Nanomagnetism is a rapidly expanding area of research which appears to be able to provide novel applications. Magnetic molecules are at the very bottom of the possible size of nanomagnets and they provide a unique opportunity to observe the coexistence of classical and quantum properties. The discovery in the early 90's that a cluster comprising twelve manganese ions shows hyteresis of molecular origin, and later proved evidence of quantum effects, opened a new research area which is still flourishing through the collaboration of chemists and physicists. This book is the first attempt to cover in detail the new area of molecular nanomagnetism, for which no other book is available. In fact, research and review articles and book chapters are the only tools available for new comers and the experts in the field. It is written by the chemists originators and by a theorist who has been one of the protagonists of the development of the field, and is explicitly addressed to an audience of chemists and physicists, aiming to use a language suitable for the two communities.

This book is intended to collect in one place as much information as possible on the use of EPR spectroscopy in the analysis of systems in which two or more spins are magnetically coupled. This is a field where research is very active and chemists are elbow-to-elbow with physicists and biologists in the forefront. Here, as in many other fields, the contributions coming from different disciplines are very important, but for active researchers it is sometimes difficult to follow the literature, due to differences in languages, and sources which are familiar to, e. g. , a physicist, are exotic to a chemist. Therefore, an effort is needed in order to provide a unitary description of the many different phenomena which are collected under the title. In order to define the arguments which are treated, it is useful to state clearly what is not contained here. So we do not treat magnetic phenomena in conductors and we neglect ferro- and antiferromagnetic resonance. The basic foundations of EPR spectroscopy are supposed to be known by the reader, while we introduce the basis of magnetic interactions between spins. In the first two chapters we review the foundations of exchange interactions, trying to show how the magnetic parameters are bound to the electronic structure of the interacting centers.

This text presents a detailed view of the calculation methods involved in the magnetic properties of transition metal complexes. Starting at an elementary level, it proceeds gradually through theory and calculations to offer sufficient background for original work in the field.
No specialized knowledge of magnetism is assumed in the introductory chapters, which offer basic definitions and generalizations of magnetic behavior and briefly review both crystal field theory and perturbation theory. Succeeding chapters explore calculations of the magnetic properties of cubic and axially distorted complexes. Featuring the complete calculation for spin-orbit coupling and magnetic field perturbations for one d-configuration, the text also discusses derivations and results for other configurations. Other topics include the magnetism of polynuclear species, in which antiferromagnetic ordering occurs over small numbers of centers. Detailed calculations by the dipolar coupling approach are given, and the results are applied to a number of studies from the literature.