Exchange Bias In Magnetic Multilayer Systems, Ferromagnetic Resonance And Spin-wave Nature Of The Study

There has been a great deal of interest in recent years in artificially engineered nano-structured materials with novel physical properties. One of particular interest is that of magnetic multilayers comprised of thin magnetic layers separated by thin non-ferromagnetic layers. They display some unusual physical properties, such as magnetic anisotropy, interlayer exchange coupling, giant magnetoresistance (GMR) and abnormal magneto-optical (MO) effect, and new applied prospects. The exchange bias effect, which arises from the interfacial exchange coupling between a ferromagnet (FM) and an antiferromagnet (AFM), was discovered more than 40 years ago. Recently, the effect has attracted much attention due to its application to giant magnetoresistive spin-valve heads for high-density recording systems. In order to understand the origin of this phenomenon, many experimental and theoretical results have been reported. In this thesis, the exchang bias, ferromagnetic resonanc and spin wave are studied.Recently many methods have been used to measure the exchange bias. The reversible measurement techniques, such as ac susceptibility and ferromagnetic resonance (FMR), other than the basic hysteresis loop measurement where the shift of loop corresponds to the exchange bias, have been used to determine the exchange anisotropy in exchange coupled bilayer systems. At the same time, many experimental results show that the characteristics of the exchange bias in FM/AFM bilayers not only depend on constituent of materials, but also on micro-structure of materials, such as size of particle, structure and rough of interface and so on. Meanwhile, the method and condition of growth of sample will affect the exchange bias.In this paper, we study the in-plane exchange anisotropy and spin wave (that is ferromagnetic resonance) in a ferromagnetic (FM)/antiferromagnetic (AFM) bilayer under stress field. Both cubic and uniaxial magnetocrystalline anisotropies are taken into account for the FM layer, while the AFM layer is only considered as uniaxial...