DAMAGE IN GARNET FILMS PRODUCED BY MULTIPLE ION IMPLiO?TATION

The dynamic response of 1 pm diameter bubbles propagating along 5 pm period, ion-implanted contiguous disk propagation tracks, fabricated on EulbGaIG/GdYTmGaIG composites has been investigated using stroboscopic techniques. A pulsed laser magneto-optic system was used to determine the bubble position on the track as a function of the rotating field phase, and from this data velocity variations during the field cycle were obtained. Comparison of bubble motion at 155 KHz on the so-called super, good and bad tracks, as defined in (1) reveals very irregular bubble motion which is strongly influenced by the combined effects of pattern geometry and track orientation with respect to the crystal symmetry of the garnet drive layer. The nonuniformity in the instantaneous bubble velocity arises from instabilities in the position of the driving charged wall as a result of the tridirectional anisotropy