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Gilbert's damping constants, [alpha], of Ni-Fe and Ni-Co thin films are determined by Q-band ferromagnetic resonance (FMR) analysis. [alpha] is calculated from the resonance width of the FMR spectrum, [alpha] of [Ni.sub.85] [Fe.sub.15] film is found to be 0.0034, which is one-fourth of those of Ni film ([alpha] = 0.013) and Co ([alpha] = 0.013). [alpha] of the [Ni.sub.100-x] [Co.sub.x] specimens increases with decreasing the Co concentration from 100 to 68 at %, and the [alpha] value of [Ni.sub.32] [Co.sub.68] film has the maximum value of 0.0021. The [alpha] values of the Ni-Co specimens are nearly the same as those of the Co-Cr-Ta and the Co-Cr-Pt. Index Terms--Damping constant, ferromagnetic resonance, Ni-Co alloy thin film, Ni-Fe alloy thin film.

In FePt(10 nm)--FeRh(25 nm), a large reduction of coercive field in the FePt layer occurs at a temperature just above the antiferro--ferromagnetic transition temperature of FeRh, which is attributable to the existence of an exchange spring mechanism. FePt(10 nm)--FeRh(7.5 nm) film does not show coercivity reduction due to the magnetic transition because of a high nucleation field for magnetization twisting of FeRh layer. The coercive field of the FePt layer is largely enhanced by field annealing. Index Terms--Coercive force, FePt-FeRh, interlayer exchange, magnetic films.