Abstract
Néel walls have been generally observed in Permalloy films below a certain thickness whereas thicker films seem to support Bloch walls or cross-tie walls. Two coupled Permalloy films of 81% Ni-19% Fe composition separated by a layer of silicon monoxide were used to study domain wall interactions. Néel walls with no Bloch lines were observed in 900-Å coupled film segments with 300-Å film separation. In a single layer of Permalloy of this thickness, Bloch walls predominate. Since the separating layer is an insulator and nonferromagnetic, the interaction is thought to be magnetostatic. The films were prepared in a step fashion on a single substrate so that uncoupled and coupled portions of a film, prepared in the same evaporation, could be observed simultaneously using Bitter powder pattern technique. Multiple-step coupled structures of varying film thickness with constant separation and varying separation with constant film thickness were prepared with thicknesses chosen in the region of Néel-Bloch transition. The coercive force of the coupled film segments is lower than that of similar uncoupled film segments. The coercive force starts to decrease at film separations of approximately 1100 Å.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.