Effects of an oscillating field on magnetic domain patterns: Emergence of concentric-ring patterns surrounding a strong defect.
Oscillating fields can make domain patterns change into various types of structures. Numerical simulations show that concentric-ring domain patterns centered at a strong defect are observed under a rapidly oscillating field in some cases. The concentric-ring pattern appears near the threshold of spatially uniform patterns in high-frequency cases. The threshold is theoretically estimated and the theoretical threshold is in good agreement with numerical one in a high-frequency region. The theoretical analysis gives also good estimations of several characteristics of domain patterns for high frequencies.
Kudo
Kazue
K
Ochadai Academic Production, Division of Advanced Sciences, Ochanomizu University, Bunkyo-ku, Tokyo 112-8610, Japan. kudo.kazue@ocha.ac.jp