Ion-implantation conditions and annealing effects for contiguous disk bubble devices

A systematic study of the anisotropy field change (\DeltaH_{k}) in magnetic garnet films under various ion-implantation and annealing conditions was performed. For most ions the maximum\DeltaH_{k}which could be obtained with the materials used was about 3000 Oe. However for hydrogen ion implantation the measured value showed no such saturation effect up through the highest damage level employed (2.0 eV/ų) at which point\DeltaH_{k}was 16500 Oe. Multiple ion implantation with mixtures of hydrogen and limited amounts of heavier ions (e.g. He or B) yielded values of\DeltaH_{k}well beyond the saturation values seen with the heavier ions alone. Post annealing propagation margins of 16% of mid-bias for propagation patterns having a cell size of 30 μm²were measured.