Interaction of stress and magnetic properties in patterned copper-nickel-copper thin films

In recent years, the epitaxial Cu/Ni/Cu thin film system has been extensively studied, due to its wide range of perpendicular magnetization. It has proved to be a model system to explore the interactions of strain, surface energies and magnetic properties. For that reason, is also an ideal system to explore the effects of patterning. It is expected that the miniaturization of patterned magnetic devices will be accompanied by a transition from polycrystalline to epitaxial films. This transition will require a detailed theoretical understanding of the interaction of strain and magnetic properties in patterned epitaxial magnetic thin films. The Cu/Ni/Cu film system is used in this work to explore a triaxial model for an orthorhombic symmetry of strain. By patterning the Cu/Ni into nanolines and measuring the resulting magnetic anisotropy, the validity of the model has been tested. It has been shown that upon patterning certain thicknesses of nickel into nanolines, the easy axis of magnetization shifts from out of the film plane to in-plane, transverse to the line direction, an observation at odds with the direction of magnetization predicted by shape considerations alone. This transition is explained by the dominant magnetoelastic energy for the Cu/Ni/Cu nanoline system.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Friend, Elizabeth, Ph. D. Massachusetts Institute of Technology

Advisor dc:contributor.advisor

• Caroline A. Ross and Robert C. O'Handley.

• Materials Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/38517

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/38517