  During the past ten years nanostructures have been subject of active
research. Fabrication of such systems follows well developed methods. The
increase in the number of materials available for research and applications
requires that the methods of their characterization be even more precise then
before. Thin film structures have many advantages for technological
applications because of compatibility with integrated circuit design. The
magnetoimpedance, MI (change of impedance of a ferromagnet on application of a
field) in 3-layered structures consisting of two magnetic layers separated by a
non-magnetic conductive layer has been predicted to show high MI. In many cases
the experimental values of MI effect are smaller than the theoretical
predictions. Therefore, more careful characterization of the samples is a must.
Accordingly, the first part of the present research deals with a ferromagnetic
resonance, FMR, study of thin films and multilayers containing Fe20Ni80 layered
nanocomponents. The second system proposed for ferromagnetic resonance study
consists of Co/GdCo multilayers prepared by rf-sputtering. It was chosen as a
model system both for convenience and in view of possible applications. The
third group of magnetic materials for FMR characterization consists of powders:
commercial polystyrene beads (Dynabeads-480) and CoNi powders with nanoscale
particle dimensions. These particles have many biomedical applications. FMR and
microwave absorption in micron size powders have been studied previously. More
recently new methods of small particle fabrication have been developed.
Therefore their characterization by microwave methods is highly desirable.
