Switchable lossy/non-lossy permalloy thin films

We report on the change in magnetic properties of rf sputtered Ni/sub 81/Fe/sub 19/ films of variable thickness with 0.3/spl times/0.3 mm arrays of 100 /spl mu/m holes defined upon the film using photolithographic processing, and 50 /spl mu/m and 100 /spl mu/m diameter holes of variable array density defined using laser ablation. The 10 Hz BH loops, 10 to 500 MHz complex permeability spectra, and domain patterns of patterned, single layer rf sputtered Ni/sub 81/Fe/sub 19/ thin films were measured. A switchable lossy/non-lossy regime could be obtained by either adjusting the thickness of the film or spacing of the hole array.