Systems with competing energy scales are widespread and exhibit rich and subtle behaviour, although their systematic study is a relatively recent activity. This text presents lectures given at a NATO Advanced Study Institute reviewing the current knowledge and understanding of this fascinating subject, particularly with regard to phase transitions and dynamics, at an advanced tutorial level.
Both general and specific aspects are considered, with competitions having several origins; differences in intrinsic interactions, interplay between intrinsic and extrinsic effects, such as geometry...

Magnetism encompasses a wide range of systems and physical phenomena, and its study has posed and exposed both important fundamental problems and many practical applications.
Recently, several entirely new phenomena have thus been discovered, generated through cooperative behaviour which could not have been predicted from a knowledge of one-spin' states. At the same time, advances in sample preparation, experimental technique, apparatus and radiation sources, have led to increasing precision in the investigation and exposure of greater subtleties in magnetic thin films, multilayers and...