Argonne National Laboratory

Upcoming Events

Magnetic Vortices in Motion

Materials Science Colloquium
Valentyn Novosad (MSD)
November 14, 2013 11:00AM to 12:00PM
Building 241
The Materials Science Colloquium will be held in the Energy Sciences Building 241, Room D172.

Magnetic phenomena have been an essential facet of everyday life, most remarkably in recent times with data recording and storage. The magnetic behavior of spin assemblies is governed by the competing contributions from the short-range exchange and long range dipole-dipole interactions. Geometric confinement alters the energy landscape of mesoscale magnets leading to the appearance of unusual magnetic states, such as spin vortices [1].

In this talk I will overview our recent work in this emergent field of research, focusing on the dynamics of interacting vortices [2], controlling the vortex cores and their collective excitations [3], as well as on the biomedicine- relevant rheological properties of unbound spin vortex microdiscs [4].

[1] V. Novosad, K. Yu. Guslienko, H. Shima, Y. Otani, K. Fukamichi, N. Kikuchi, O. Kitakami, and Y. Shimada, “Nucleation and annihilation of magnetic vortices in sub-micron permalloy dots”, IEEE Trans. Magn., 37 (2001) 2088.

[2] K. S. Buchanan, P. E. Roy, M. Grimsditch, F. Y. Fradin, K. Yu. Guslienko, S. D. Bader and V. Novosad, “Soliton pair dynamics in patterned ferromagnetic ellipses”, Nature Physics. 1, 172-176 (2005).

[3] S. Jain, V. Novosad, F. Y. Fradin, J. E. Pearson, V. Tiberkevich, A. N. Slavin and S. D. Bader, “From chaos to selective ordering of vortex cores in interacting mesomagnets”, Nature Communications. DOI: 10.1038/ncomms2331 (2012).

[4] D.-H. Kim, E. A. Rozhkova, I. V. Ulasov, S. D. Bader, T. Rajh, M. S. Lesnak, and V. Novosad, “Biofunctionalized magneticvortex microdiscs for targeted cancer-cell destruction”, Nature Materials, 9, 165 - 171 (2010).

The work and the use of the Center for Nanoscale Materials at Argonne National Laboratory were supported by UChicago Argonne, LLC, Operator of Argonne National Laboratory (Argonne). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357.