Inelastic light scattering in magnetic dots and wires

Abstract

An overview of the current status of the study of spin wave excitations in arrays of magnetic dots and wires is given. We describe both the status of theory and recent inelastic light scattering experiments addressing the three most important issues: the modification of magnetic properties by patterning due to shape anisotropies, anisotropic coupling between magnetic islands, and the quantization of spin waves due to the inplane confinement of spin waves in islands.

A study of the non-uniform effect on the shape anisotropy in patterned NiFe films of ferromagnetic resonance

“…Spin-wave spectra were observed for continuous NiFe films only when the thickness was much greater than ours, about 100-300 nm, and according to the early theory the separation of peaks is inversely proportional to the square of the film thickness and the wavelength number, which does not fit with our results quantitatively. Our data are similar to the characteristics of the recent spin-wave excitation by Brillouin light scattering [10,11],in which, however, the static field was in the film plane, while in this paper the field was along the film normal. In addition, the multiple peaks observed in our patterned rectangular elements when the steady field is along the film normal show the characteristic linear relation of the resonance field with the mode number, including the excitations of both odd and even modes.…”

“…In addition, it probes magnetization non-uniformity and excitations such as magnetostatic modes and spin waves in thin films [6][7][8][9][10][11][12][13][14]. However, FMR study of patterned magnetic structures is scarce.…”

Spinwaves in Laterally Confined Magnetic Structures

“…Due in to the constant increase the areal density of information in magnetic storage, a large amount of work has been performed on arrays of submicrometer-scale magnetic dots, which are expected to replace continuous thin magnetic films as storage media within the next few years [1,2,3,4,5]. Patterned magnetic structures are also very interesting from the basic research point of view.…”

Magneto-Optical Kerr Effect Enhancement Methods for Nanostructures

“…The magnetic dynamics in nanostructures are distinguished from thin films due to the confined geometry and corresponding boundary conditions [1]. Furthermore, the experimental measurements of the nanostructures have additional difficulties due to the small volume of the ferromagnetic body that causes small signals in most measurement methods.…”