Correlation of edge roughness to nucleation field and nucleation field distribution in patterned Permalloy elements
J. W. Lau and R. D. McMichael
Metallurgy Division, National Institute of Standards and Technology, Gaithersburg, MD 20899
Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973
For magnetic devices, the trend toward nanostructures increases the boundary-to-volume Ratio and emphasizes the role of edges on switching behavior in applications such as magnetic memory chips and patterned-media hard drives. For both technologies, the `bits' are nano-islands of magnetic material that ideally have identical switching fields. In reality, however, there exists a switching-field distribution (SFD) due to subtle differences among the bits on the Nanoscale. Understanding the origin of SFDs is important because a broad SFD reduces both bit density and memory reliability. In this work, we examine edge roughness as a nanoscale non-uniformity, and find direct correlations to both the switching field and the SFD for switching by vortex nucleation. These results bridge an important gap in the understanding of how physical edge attributes alter switching behavior, providing guidelines for the design of new high-density data storage devices.
************************************************************************
************************************************************************
Name: June Lau
Mentor: Robert McMichael
Laboratory: MSEL
Room: B142
Building: 223
Mail Stop 8552
Telephone #: x5711
FAX #: x4553
Email: june.lau@nist.gov
Category: Physics
Not a Sigma Xi member.