29 巻 (2005) 2 号 p. 132-137
To develop micromagnetic devices for microwave applications, it is necessary to develop magnetic films with a ferromagnetic resonance (FMR) frequency higher than 1 GHz. For this purpose, it is essential that such films should have both high saturation magnetization and large magnetic anisotropy. In the present study, an exchange-coupled multilayer film, consisting of Fe89Si11(at.%) with a saturation magnetization of 19 kG and Mn80Ir20(at.%), was fabricated and characterized. From the experimental results, the Mn-Ir/Fe-Si exchange energy Jex was estimated to be about 0.1 erg/cm2. The [Mn-Ir (10 nm)/Fe-Si (7.2 nm)]21/Mn-Ir (10 nm)/Fe-Si (3.6 nm) multilayer film exhibited FMR at around 6 GHz. In addition, μ' was estimated 40-80, and μ” was nearly equal to zero at low frequencies (f < 4.5 GHz). The exchange bias magnetic field was decreased by thermal process. If the decrease of the FMR frequency due to thermal process is allowed by 10 % of as deposited film, the maximum process temperature must be lowered by 250 °C.