Dynamics effects in thin ferromagnetic films /
Dynamics effects in the ferromagnetic thin films below and above the reorientation transition if studied. Particular attention is given to the effects of the dipole-dipole interaction on the spin-wave dynamics above the transition and the dynamics and decay of the topological excitations below the t...
| Main Author: | |
|---|---|
| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1998.
|
| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=732838021&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Dynamics effects in the ferromagnetic thin films below and above the reorientation transition if studied. Particular attention is given to the effects of the dipole-dipole interaction on the spin-wave dynamics above the transition and the dynamics and decay of the topological excitations below the transition. The dipole- dipole interaction, although irrelevant for the 3D magnet, plays a major role for the 2D systems in the long wave-length limit. It is found that the dipole-dipole interaction for the 2D XY magnet leads to the transformation of the dispersion relation. A spinwave propagates by an anomalous anisotropic diffusion with the dispersion relation: [iapcxw/ftlkp] and [il.ulxkzikir ], where [Ly ]= 47/27 and [iz] = 47/36. The existence of easy-axis p anisotropy below the reorientation transition modifies the topological excitations - the Skyrmions. Skyrmions are the magnetic defects in an ultrathin magnetic film, similar to the bubble domains in the thicker films. Even weak uniaxial anisotropy determines its radius unambiguously. The dynamics of the Skyrmion decay is considered. The discreteness of the lattice in an isotropic 2D magnet leads to a slow rotation of the local magnetization in the Skyrmion and, provided a small dissipation, decay of the Skyrmion. The radius of such a Skyrmion as a function of time was calculated. The uniaxial anisotropy stabilizes the Skyrmion. The relaxation process is also studied. A great attention is paid to the possible experimental observation of the phenomena discovered. |
|---|---|
| Item Description: | Vita. |
| Physical Description: | viii, 66 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references: pages 46-49. |