Ferromagnetic resonance and antiresonance in glass-coated amorphous microwires

We report magnetoabsorption measurements on micron-size wires of (Co100-xFex)(72.5)Si12.5B15 at frequencies of 9.7, 26.7, 32.7, and 56 GHz, that is where the electromagnetic skin depth is comparable to the radius. The observed spectra are quite unconventional. In order to understand them, it is necessary to take explicit account of the variation of the RF fields inside the cylindrical sample and then express the absorption in terms of the concomitant permeability tensor. (C) 2002 Elsevier Science B.V. All rights reserved.