Search

Differential domain‐wall propagation in the surface layers and interior of single‐crystal c‐axis‐oriented 75‐μ‐thick Sm0.55 Tb0.45 FeO3 platelets has resulted from high surface coercivity induced by mechanical polishing. Cylindrical magnetic domains with measured wall coer‐civities of 0.5 Oe were formed inside the platelets following saturation of the surface magnetizations. The magnetized surfaces imposed a self‐biasing effect on the bubbles. These bubbles were propagated at 100 Hz with a Permalloy T‐bar shift register.

Unusual cylindrical magnetic bubble domains completely bounded by domain walls have been stabilized inside YbFe03 platelets with high surface coercivities. The energy density of the walls forming the cylinder ends manifests itself as an effective bias field, which, for platelet thicknesses between 55–75μ, stabilizes bubbles in zero applied field. Annealing at 700°C for one hour reduced the coercivity associated with bubble propagation to 0.25 Oe. A theoretical analysis of the stability and coercivity of these self‐biased bubbles is given.