CHARACTERISTIC TEMPERATURE-DERIVED HARD BUBBLE SUPPRESSION

CHARACTERISTIC TEMPERATURE-DERIVED HARD BUBBLE SUPPRESSION Normal single wall magnetic or "bubble" domains are generated in bubble domain materials without generating hard bubble domains by selecting the composition based upon a predetermined minimum temperature. This hard bubble suppression is based upon the fact that a bubble domain material of a given composition has a characteristic temperature, TH, above which hard bubble domains are not generated. By selecting the composition to set TH equal to or less than the minimum ambient temperature for the bubble domain material, hard bubble generation is precluded. Means may be provided for maintaining the bubble domain material at or above TH.