Date of Award
Doctor of Philosophy
The study of low-dimensional magnetic microstructures has become increasingly active and important because of the recent advances in sample growth techniques and the potential applications of structures to technology. The theoretical study of the spin-wave excitations in these magnetic structures is important to understand many physical properties of these structures. The aim of this thesis is to study the exchange-dominated spin waves in ferromagnetic layered structures, especially those structures with one-dimensional (1D) translational symmetry.;The general method used in this thesis is a quantum-mechanical Green function theory formulated within a microscopic approach. However, a particular matrix diagonalization technique is developed to calculate analytically the spin-spin Green functions for the layered structures with 1D and 2D translational symmetry.;The ferromagnetic single-layered structures investigated are complete films, perpendicularly truncated films (including long rods or wires), perpendicular interfaces in "binary" films with thickness, and thin films with surface steps; whereas the ferromagnetic multilayer structures investigated are conventional superlattices (with 2D translational symmetry) and perpendicularly truncated (or cleaved) superlattices. The spin-spin Green function expressions are obtained for these layered structures. The dispersion relations and spectral intensities of the bulk and surface spin-wave modes in these ferromagnetic structures are then calculated explicitly. The finite-size effects on the spin waves are discussed by numerical examples and the asymptotic behavior of the spin waves is examined in various types of geometrical limits.;The Green function results obtained in this thesis are also useful in calculating many other experimentally observable quantities besides the spin-wave spectra and intensities; some examples would be the cross section for inelastic light scattering and the absorption strength in spin wave resonance. The possibilities of some extensions and applications of the theoretical results are briefly discussed.
Jiang, Linjie, "Quantum Theory Of Spin-wave Excitations In Ferromagnetic Layered Structures" (1996). Digitized Theses. 2614.