Volume 22 of the Handbook of Magnetic Materials, like the preceding volumes, has a dual purpose. With contributions from leading authorities in the field, it includes a variety of topics which are intended as self-contained introductions to a given area in the field of magnetism without requiring recourse to the published literature. It is also intended as a reference for scientists active in magnetism research, providing readers with novel trends and achievements in magnetism. Volume 22 comprises topical review articles covering perovskite manganites and their modifications, the magnetocaloric effect in intermetallic compounds and alloys, the scaling potential of particulate media in magnetic tape recording and layered iron superconductor systems. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material within the framework of physics, chemistry and material science.