| Magnetism is the basic properties of the matter. Starting from the study of the magnetism and its forming mechanism for the matter, investigating a new way to improve the performance of magnetic materials, and exploiting a new application region for magnetic materials have become main research contents and methods for the contemporary magnetism. In this paper, we apply the semi-classic spin-wave theory to investigate a perpendicular magnetization film with heterogeneity. And we also use spin-wave theory method to study the one-dimensional quantum Heisenberg model.In chapter 1, the research background, contents and methods of this dissertation are introduced.The effect of bulk heterogeneity on spin waves in a perpendicular magnetization film, are discussed in chapter 2. Making use of semi-classic spin-wave theory, the equation of motion for the magnetization intensity is obtained. The eigenfunction and eigenvalue of the equation are solved by the non-degenerate perturbation theory, as well as dispersion relations for the spin wave. Dispersion relations affected by two kind of bulk heterogeneity are analyzed.In chapter 3, the magnetic of the one-dimensional anisotropic Heisenberg antiferromagnet with S = 1/2 has been studied by means of the spin-wave theory method. The internal energy U(T) and specific heat Cm(T) are found to haveα,βthepower-law behaviors, U(T)-Tαand Cm(T)-Tβ. And the exponentsα,βare found to be dependent on the anisotropyηand the staggered magnetic field h. The ground-state energy U0 and the long-range orderω∞(η) are estimated in the zero temperature and zero field. Our result shows that the long-range orderω∞(η) does not vanish forη< 1. For the isotropic case, the long-range orderω∞, which is in agreement with the results of the isotropic chain (i.e.ω∞=0).In the last chapter, the conclusions of the whole dissertation are given, as well as prospect for the future work.
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