[PAST EVENT] Condensed Matter Seminar

March 9, 2016
3pm - 4pm
Small Hall, Room 122
300 Ukrop Way
Williamsburg, VA 23185Map this location
Domain walls in magnetic multilayered systems can exhibit a very complex and fascinating behavior.
The magnetization of thin films of hard magnetic materials is in general perpendicular to the thin-film plane, but its direction changes periodically, forming an alternating spin-up and spin-down stripe pattern. The latter is stabilized by the competition between the ferromagnetic coupling and dipole-dipole interactions, and disappears when a moderate in-plane magnetic field is applied. It has been suggested that such a behavior may be understood in terms of a self-induced stripe glassiness. In this talk I will show that such a scenario is compatible with the experimental findings. The strong out-of-plane magnetic anisotropy of the film is found to be beneficial for the formation of both the stripe-ordered and glassy phases. At zero magnetic field the system can form a glass only in a narrow interval of fairly large temperatures. An in-plane magnetic field, however, shifts the glass transition towards lower temperatures, therefore enabling it at or below room temperature. In good qualitative agreement with the experimental findings, we show that a moderate in-plane magnetic field of the order of 50 mT can lead to the formation of defects in the stripe pattern.

{{http://journals.aps.org/prb/abstract/10.1103/PhysRevB.93.054410, Reference: Phys. Rev. B 93, 054410}}