The film thickness dependence of the magnetic damping coefficient (α) was investigated by measuring the ferromagnetic resonance (FMR) of Fe 4N/NM (NM: Pt and Cu) bilayer films at room temperature. We observed that α in Fe4N/Pt films increased with increasing Fe 4N film thickness. Moreover, the enhancement of α, which is represented by the difference in the α values of Fe4N/Pt and Fe4N/Cu films, also increased as the Fe4N film thickness increased. The behavior observed in the Fe4N system was the opposite of that observed for the conventional Ni-Fe system. We speculated two mechanisms occurring in Fe4N/Pt films, which are less magnetic and/or nonmagnetic impurities in the Fe4N films and enhancement of the coercive force (Hc) with increasing Fe4N film thickness.
ASJC Scopus subject areas
- Physics and Astronomy(all)