Aimed primarily at experimental chemists, physicists, electronic engineers and material scientists interested in particulate and granular magnetic materials, this textbook is the culmination of over 40 years'' research into the subject.The text is divided into two parts. Part One covers the basic physics of magnetism from a relatively low level, including an explanation of some of the unusual terminology in magnetism such as the idea of poles and flux, whose origins are little understood. The complexity of the unit systems in magnetism are also presented. Thereafter a brief review of the principles of domain theory is presented and thermal activation effects and their correct measurement are discussed in some detail. Thetopic of exchange bias, where an antiferromagnetic material is grown in intimate contact with a ferromagnet, is presented in significant detail reviewing old theories and numerical models but then focusing on what has become known as the York Model of Exchange Bias whic