Special features of the ferromagnetic resonance in cobalt-containing granulated nanostructures

Abstract

Results of studying the concentration and orientation spectra of ferromagnetic resonance (FMR) in nanogranulated composites consisting of amorphous cobalt-containing granules in the SiO 2 or Al 2 O 3 amorphous dielectric or LiNbO 3 ferroelectric matrix are presented. It is demonstrated that the magnetic and structural changes of the nanocomposites attendant to changes in the metal phase concentration can be described using the FMR spectra.

Shape anisotropy of magnetic nanoparticles in (Co$_{86}$Nb$_{12}$Ta$_2$)$_x$(SiO$_2$)$_{1-x}$ composite films revealed by grazing-incidence small-angle X-ray scattering

“…For the lowest concentration x = 0.193 clusters with almost isotropic shape and average radius of 1 nm were observed, while for higher concentrations the average cluster length along the film normal is 1.5 − 7 nm and the cross-section is 1 − 2 nm. Therefore the grain shape anisotropy must be included into consideration of the magnetic properties of this system, such as ferromagnetic resonance studies 15,16 or absolute values of the magnetic anisotropy constant evaluation 12 .…”