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The velocity angular dispersion of Rayleigh surface and bulk acoustic modes propagating parallel to surfaces of (100), (110), and (111) SrTiO3 plats are measured by surface Brillouin scattering. Findings show that simulations fit to the experimental data on the bulk acoustic modes for the three crystal orientations yields elastic constants that are used to accurately predict the various velocity angular dispersion branches of the Rayleigh surface mode.

The topic of permanent magnetism has aroused much interest in recent years because the measured coercivity only approaches 20%-40% of the theoretical nucleation fields as derived from micromagnetic theory. Two mechanisms are proposed for the discrepancy that is the presence of hindrances to domain wall displacement and the nucleation of reversely magnetized volume.

The longitudinal magnetic-field dependence of quantized spin waves in ordered permalloy nanowire arrays in two dimensions (2D) was studied by Brillouin spectroscopy. The results were analyzed on the basis of collective spin waves in a hexagonal 2D nanowire array and compared with the results obtained from an analysis of spin waves in an isolated wire.