Propagation of linear and nonlinear spin wave excitations in YIG and Lu{sub 2.04}Bi{sub 0.96}Fe{sub 5}O{sub 12} films studied by space resolved Brillouin light scattering (abstract)
- Fachbereich Physik, Universitaet Kaiserslautern, Kaiserslautern 67663 (Germany)
- Electrotechnical University, St. Petersburg (Russia)
- Fachbereich Physik, Universitaet Osnabrueck, Osnabrueck 49069 (Germany)
- Department of Physics, Oakland University, Rochester, Michigan 48309-4401 (United States)
We have investigated the propagation of surface and backward volume spin waves (BVSW) with the in-plane wavevector k{sub {parallel}}=10{endash}900 cm{sup {minus}1} excited by microwaves in YIG and Lu{sub 2.04}Bi{sub 0.96}Fe{sub 5}O{sub 12} (LBIG) films with the film thicknesses 5 and 1.5 {mu}m, respectively. In all cases the magnetization and k{sub {parallel}} were in the film plane. The frequencies of the spin wave excitations as well as the spatial distribution of their intensities in the linear and in the nonlinear excitation regime were measured by means of a high-stabilization, small-angle Brillouin light scattering setup with a spatial resolution of 30 {mu}m. It is well-known that in the case of BVSW modes, the Lighthill criterion for modulational instability is fulfilled for both the longitudinal and the transverse perturbations of the initially constant-amplitude wave beam. Therefore, this mode is very much suitable for the investigation of the evolution of a plane-front, constant-amplitude initial beam, and for a direct experimental study of two-dimensional nonlinear diffraction effects of the beam leading to self-focusing. The garnet films with in-plane dimensions of 2{times}10 mm{sup 2} were grown by liquid phase epitaxy onto a single crystalline (111)-oriented gallium gadolinium garnet substrate. Two strip antennas, 35 {mu}m wide and situated at the ends of the films, were used for the excitation of the spin waves and for monitoring. The working frequency was 8.10 GHz. Special efforts were taken to minimize the beam divergence. For all nonlinear studies the initial angular beam divergence was not larger than {Theta}{sub max}=0.05 rad. In the linear regime the attenuation factor was measured, and the reflection of the spin waves from the sample boundaries was studied. We also observed the interference between the two lowest order lateral modes having different initial spatial distributions of the magnetization. (Abstract Truncated)
- OSTI ID:
- 554255
- Report Number(s):
- CONF-961141-; ISSN 0021-8979; TRN: 9709M0097
- Journal Information:
- Journal of Applied Physics, Vol. 81, Issue 8; Conference: 41. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 12-15 Nov 1996; Other Information: PBD: Apr 1997
- Country of Publication:
- United States
- Language:
- English
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