High-frequency ferromagnetic resonance in Nd/sub 2/Fe/sub 14/B//spl alpha/-Fe nanocomposite films

Thin-film magnets, composed of nanophase dispersed Nd/sub 2/Fe/sub 14/B and /spl alpha/-Fe have been synthesized by rf magnetron sputtering. With increasing /spl alpha/-Fe volume fraction V/sub Fe/, the saturation magnetization increased linearly, while the coercivity decreased. Ferromagnetic resonance measurements were made by using a high-frequency and high-field ESR apparatus, which exhibited two absorption peaks. A model calculation of the resonance field was made for a simplified hard/soft two-sublattice system to analyze these results. Estimated values of the exchange-coupling constant are in good agreement with those deduced from micromagnetic analysis of the magnetization curves.