Magnetism in thin films

In the last decade enormous effort has been made in research and investment to study magnetic properties of thin films because of their obvious practical applications. Coincidentally, it happens that theory has made enormous progress. Ab initio calculations and microscopic theories allow us for the first time in the history of magnetism to study and manipulate the magnetism on an atomic scale. In contrast to bulk magnetic materials, ultrathin films allow us to manipulate magnetism via the thickness and, by use of artificial structure growth, to produce structures which do not appear in nature. Here we discuss the fundamental magnetic observables, i.e. magnetization, Curie temperature, magnetic moment per atom, susceptibility and magnetic anisotropy, for idealized prototype thin films like Fe, Co, Ni on metal substrates such as Cu, W, Re. Finally, we present studies on trilayers, i.e. magnetic thin films separated by a spacer, like Cu. These trilayers present prototypes of interlayer coupling relevant for practical use of multilayer structures.