SIZE-DEPENDENT SPIN-WAVE FREQUENCY IN FERROMAGNETIC WIRE-ARRAY STRUCTURES

Spin-wave frequency measurements in ferromagnetic FeNi wire-array stru ctures by Brillouin light scattering (BLS) are reported. The arrays st udied were 600 Angstrom thick and had wire widths of between 0.8 and 1 0 mu m, with separations between wires of twice the width. The spin-wa ve frequencies were measured in the Voigt geometry with an external fi eld applied parallel or perpendicular to the wires. A rapid drop in BL S intensity with decreasing structure size was seen. For the perpendic ular field geometry, we observed a decrease in both the surface and fi rst volume-mode frequencies. We show this to be due to static demagnet izing fields. The parallel field case showed a rise in frequency of on ly the surface mode with decreasing wire size, which we demonstrate to be the effects of oscillating magnetic edge charges. [S0163-1829(98)0 4021-1].