Ripple field effect on high-frequency measurements of FeTiN films

Abstract

Ferromagnetic resonance and permeability linewidths of high-moment FeTiN thin films have been recorded and analyzed using ripple theory in order to separate inhomogeneous broadening from the intrinsic damping of the material. These results are compared to the analysis of the same phenomenon using a simple but common model of amplitude dispersion. The ripple is also used to analyze the behavior of the resonance frequency of a sample when rotated in low fields.

Annealing temperature dependence of microwave permeability in CoFe/MnIr bilayers

“…where α 0 is the intrinsic damping constant and H r is the ripple field, which means the angular distribution of the anisotropy field [11]. The extracted α G values are well agreed with the calculated ones using the Eq.…”

“…Figure 3(b) shows the exchange bias field dependence of the α G , which monotonously decreases with the exchange bias field. This behaviour can also be explained by the ripple field model introducing the angular distribution of the anisotropy field in order to separate the inhomogeneous broadening of imaginary permeability from the intrinsic damping [11]. The broadening of α G in exchange biased F/AF bilayers can be expressed as follows:…”

Ferromagnetic resonance in soft Cu/FeCo

“…(8), there is 21 Oe worth of broadening in the absorption spectrum. This is in line with the previous results and is probably due to the small grain size [13]. We turn to rotation data to help us interpret the difference in the Gilbert parameter in the two orientations.…”

FeCoHfN thin films fabricated by co-sputtering with high resonance frequency

“…According to Hoffmann, there is an additional effective isotropic field that contributes to the anisotropy field obtained from permeability spectra in addition to the static intrinsic anisotropy field. This additional effective field dependent on a so-called ripple constant may originate from the local random anisotropies which are in isotropic distribution [18][19][20][21] and as a result it is not included in H sta K from the static measurement as that from the dynamic measurement [19,20]. The difference between H sta K and H dyn K may be assigned as rotatable magnetic anisotropy field (so-called dynamically induced internal field or ripple field) [22].…”