The Handbook of Magnetic Materials has a dual purpose; as a textbook, it provides an introduction to a given topic within magnetism, and as a work of reference, it serves scientists active in magnetism research. To fulfill these two goals, each chapter in the Handbook is written by leading authorities in the field, and combines state-of-the-art research results with an extensive compilation of archival knowledge. Magnetism is a rapidly expanding field which constantly continues to encompass new phenomena. Examples of such subfields of magnetism are quadrupolar interactions, magnetic superconductors, and quasiscrystals: topics that are all covered in the present volume. The only common ground between these new materials and ferromagnets, is the possession of a magnetic moment; the series title has been slightly adjusted to reflect this. But in keeping with tradition, the Handbook of Magnetic Materials continues to allow readers to acquaint themselves in great depth with topics through the entire breadth of magnetism research.