Fabrication, characterization, and micromagnetic analysis of lithographically defined particle arrays for applications in data storage

In this thesis, the magnetic behavior of nanostructured ferromagnetic particle arrays are studied by experiments and numerical micromagnetics for ultra-high-density data storage applications. 1 00nm or 200nm period arrays of nanostructured nickel, cobalt, and cobalt phosphorus are fabricated by the techniques of interference lithography combined with evaporation and electrodeposition. The nanomagnet arrays are characterized by bulk magnetometry and magnetic force microscopy. The remanent states of evaporated conical particles and electrodeposited cylindrical particles are studied by micromagnetic simulations and compared with experimental measurements. For electrodeposited particles, the influence of size, aspect ratio and microstructure on switching field is also investigated. Finally, the effect of demagnetizing magnetostatic interactions and switching field spread on the squareness and the shape of hysteresis loops is studied with the help of an Ising-like interaction model. Based on these observations, a stability condition for patterned media is found and used for determining the optimum spacing between nanomagnets.

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

2001

Author dc:creator

• Hwang, Minha, 1973-

Advisor dc:contributor.advisor

• Caroline A. Ross.

• 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/1721.1/8449

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8449