Magnetization buckling in chevron column bubble detectors

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Abstract
Magnetic domain behavior is studied in several types of chevron stretcher detectors using ferrofluid and in-plane fields in two orthogonal directions. The importance of magnetization buckling in the response of these detector columns is confirmed. Analogous behavior was found in a closed loop of Permalloy since in both cases the natural minimum energy state is one of saturation with continuous flux flow. Two types of magnetization buckling can be distinguished-for reversal along the whole detector column or in alternate chevron limbs. Switching fields for reversal along the column are measured and their dependence on column geometry and film thickness Characterized. Changes in detector magneto-resistance are measured for the same applied fields and the shape of these signals is consistent with the observed domain processes. Also the percentage change in resistance is in line with that calculated on the basis of a simple domain model. For a detector in a uniform rotating field, reversal by magnetization buckling accounts for both the ω:2ω transition and the 2ω:4ω transition in stronger fields.