一维磁振子晶体带隙结构与磁晶各向异性的研究

Band Structure of Exchange Spin Wave in One-dimensional Magnonic Crystals with Effect of Uniaxial Anisotropy

从铁磁材料中自旋波传播满足的局域动力学方程,即Landau-Lifshitz方程出发,在仅考虑短波微扰的情况下,采用平面波展开法推导出了用于数值计算带结构的本征方程,数值计算了一维磁振子晶体带结构,并考虑了磁晶各向异性效应、体积填充率对磁振子晶体带结构的影响。结果表明:磁晶各向异性效应对带隙的产生具有不可忽略的作用,考虑磁晶各向异性效应后,可将未考虑该效应情况下的各个填充率下的第一个带隙宽度约降低其一半,对第二、第三带隙宽度也有明显的降低效果。

In this thesis,the Landau-Lifshitz equation can describe the localized dynamics of spin waves in ferromagnetic materials.Considering the short-wave perturbation,the band structure of spin waves in one-dimensional magnonic crystals was calculated using plane wave expansion method.The effects of magnetic anisotropy and volume filling fraction of composites on the spin-wave band gaps of magnonic crystals have been investigated.The numerical results showed that spin-wave gaps would be generated under the definite range of filling fraction rations,and the effect of magnetic anisotropy was non-negligible to form the band gaps.In contrast to the gap width of the first band without effect of uniaxial anisotropy of composites,the gap width of the first band was decreased about 50%.Correspondingly,the gap width of the second and third band are both decreased.