Static characterization of magnetic bubble films

A.C. susceptibility and optical interference are combined to determine the material length, saturation magnetization and thickness of garnet bubble films on GGG substrates. These measurements have been automated to provide precisions of better than 1% and throughputs of more than sixty wafers per hour. Derived values of material length and saturation magnetization agree to better than ±3% with those from visual measurements of stripe width and bubble collapse field for a single film composition. Disagreement between results from two film compositions possibly points up a fundamental difference between the measurement techniques.