Great interest to of multilayer magnetic structures since the middle 80s of the 20th century has been originated by a pronounced progress in production of superthin metallic films. For some years their fascinating (from fundamental and applied standpoints) properties, such as antiparallel ordering of ferromagnetic layers, giant magnetoresistance, sign-changing oscillations of interlayer exchange, non-collinear interlayer ordering of magnetic moments, have been observed.
Along with the attractive similarity of their technology to the one commonly used in microelectronics, these materials are very promising for future development of miniature sensors of magnetic field, nonvolatile memory of electronic devices and so on. As of now, some of them has been realized in large-scale commercial products, such as read-heads of hard disks, while others are waiting their time. The discovery in this field was acknowledged
by the Nobel Prize (2007), conferred to
A. Fert and P. Grünberg “for discovery of giantmagnetoresistivity effect”. The system Fe/Cr/Fe occupied a special place in those studies. It is this system that exibited for the first time the most interesting phenomena, which have generated an explosion in physics of magnetic films. Nevertheless the nature of exchange interactions in this system remained under debate. This was primarily relevant to the complex phase diagram of a chromium spacer and the crucial dependence of sample properties on technologyrelated perfection of its structure. The paper briefly reports the main experimental and theoretical studies of the multilayer Fe/Cr/Fe systems and present the results by the authors which elucidate the mechanism responsible for interlayer coupling in this system.
PACS: 75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects; PACS: 75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures); PACS: 76.50.+g Ferromagnetic, antiferromagnetic, and ferrimagnetic resonances; spin-wave resonance.
Key words: multilayer magnetic structures, exchange interactions, magnetization curves.