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Schiffer, Peter E Cooper, Lance Dahmen, Karin A. Abbamonte, Peter M. Gilbert, Ian 2015-07-22T22:15:58Z 2015-07-22T22:15:58Z 2015-05 2015-02-27 Artificial spin ice is a class of arrays of interacting ferromagnetic nanoislands that are used to experimentally model Ising spin systems. It has been successfully used to understand the behavior of frustrated spin systems, particularly the class of magnetic pyrochlore oxides known as spin ice. Here I describe a series of experimental studies that further extend the usefulness of artificial spin ice. First, I outline a thermal annealing technique developed to place artificial spin ice samples into their ground state, which previously-used techniques such as ac demagnetization were unable to do. Second, the shakti lattice, a new lattice geometry that better mimics the behavior of real spin ice, is described. Third, a series of experiments using artificial spin ice to explore memory effects in hysteretic systems is detailed. Finally, I describe real-time photoemission electron microscopy measurements of thermal fluctuations of the nanoisland magnetic moments in another new lattice geometry. All these investigations illustrate the utility of artificial spin ice in bridging the gap between experimental studies of natural materials and theoretical and numerical work. Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2015-07-22 without embargo terms The student, Ian Gilbert, accepted the attached license on 2015-02-26 at 10:15. The student, Ian Gilbert, submitted this Dissertation for approval on 2015-02-26 at 10:31. This Dissertation was approved for publication on 2015-02-27 at 08:06. DSpace SAF Submission Ingestion Package generated from Vireo submission #7728 on 2015-07-22 at 10:30:11 Made available in DSpace on 2015-07-22T22:15:58Z (GMT). No. of bitstreams: 2 Gilbert_Ian1.pdf: 22155334 bytes, checksum: 81ae7925ebce201ae9a6b5bf8afe9c02 (MD5) license.txt: 4061 bytes, checksum: 9f045a1a105e9715336575dbcdf03c1a (MD5) Previous issue date: 2015-02-27 application/pdf http://hdl.handle.net/2142/78318 Copyright 2015 Ian J. Gilbert Ising model statistical mechanics micromagnetics nanomagnetism frustrated magnetism artificial spin ice Ground states in artificial spin ice text text 2015-5 Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.