Yampolska G. Ground state and ferromagnetic resonance in bilayer exchange-coupled magnetic films

The subject of the thesis is an investigation of the influence of the interlayer exchange coupling on some static and dynamic properties of a bilayer film structure. The inhomogeneous magnetization distribution in an easy-axis/easy-plane bilayer exchange-coupled film of finite thickness has been investigated for two cases: the external magnetic field of an arbitrary orientation is larger than the layer's anisotropy fields, and the external magnetic field is perpendicular to the film plane. In the first case the influence of the interlayer exchange coupling of ferromagnetic and antiferromagnetic types on the magnetic resonance properties of the film structure has been investigated. The analytical expressions for the resonant fields and the integral high-frequency susceptibility tensor have been obtained. Two qualitative criteria have been proposed to determine a type of interlayer exchange interaction. The impedance and the surface impedance of a thin bilayer exchange-coupled ferromagnetic metal film, excited by an alternating current flowing along the film, have been calculated numerically.