Book excerpt: This book is a comprehensive design text for permanent magnets and their application. Permanent magnets are very important industrially, and are widely used in a variety of applications, including industrial drives, consumer products, computers and cars. In the early 1970s a new class of magnet - the rare earths - was discovered, the properties of which showed sustained improvement over the following two decades. New materials such as these have spawned many new markets for magnets, with significant performance gains in the devices for which they are used. Until now, however, there has been no text that unified all the relevant information on the wide range of modern permanent magnet materials. This book is a comprehensive review of the technology, intended for scientists and engineers involved in all stages of the manufacture, design and use of magnets.