Direct-current effects on magnetization reversal properties of submicron-size Permalloy patterns for radio-frequency devices

Ferromagnetic resonance (FMR) spectroscopy is used to measure direct-current (dc) effects on the magnetization reversal properties of submicron-sized lateral patterned magnetic material. The observed FMR frequency-field relationship shows that for both 240 and 550 nm wide Permalloy (Py) nanowires the coercivity is reduced by ∼33% when a 50 mA dc passes through the transmission line where the nanowires are incorporated. The temperature dependence of the coercivity has a T relationship which suggests the coherent rotation mode tendency in such 100 nm thick Py nanowires.