High frequency characteristics of NiO/(FeCo/NiO)10 multilayers with exchange anisotropy

Abstract [NiO/Fe 65 Co 35 ] 10 exchange-coupled multilayer films for high frequency applications are fabricated, and their static magnetic property and microwave permeability are studied systematically. Both exchange bias field and ferromagnetic resonance frequency of the multilayers increase with decreasing Fe 65 Co 35 thickness, which means that the microwave properties such as permeability and FMR frequency can be controlled by changing Fe 65 Co 35 thickness in the exchange-coupled films. Ferromagnetic resonance frequencies beyond 7 GHz of the films are measured and reported for the first time.