Characterization of the Magnetic Behavior of Bubble Domains

The magnetic behavior of bubble domains can be characterized by the film thickness h, the magnetization Ms, the material length ℓ, the total anisotropy K, the coercivity Hc, and the mobility μ. A particular set of measurements to evaluate these parameters is described. This set includes the determination of: (1) h using optical interference; (2) Ms and ℓ from the field dependence of the bubble diameter and also from the zero field stripe width; (3) K from the susceptibility measured in an optical magnetometer; (4) Hc from the stripe domain response to an ac field; and (5) μ by the bubble collapse and step function response methods. Considerable attention is devoted to experimental details and to possible problems that may arise in the measurements.