Domain wall velocity measurement in permalloy nanowires with X-ray magnetic circular dichroism imaging and single shot Kerr microscopy

• Published in: Journal of magnetism and magnetic materials 2010-05, Vol.322 (9), p.1347-1352
• Main Authors: Moore, T.A., Kläui, M., Heyne, L., Möhrke, P., Backes, D., Rhensius, J., Rüdiger, U., Heyderman, L.J., Mentes, T.O., Niño, M.Á., Locatelli, A., Potenza, A., Marchetto, H., Cavill, S., Dhesi, S.S.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dichroism; Domain wall dynamics; Electronic transport in condensed matter; Exact sciences and technology; Ferromagnetic nanowire; Image contrast; Imaging; Magnetic properties and materials; Magnetic properties of nanostructures; Microscopy; Nanostructure; Nanowires; Permalloy; Physics; Shot; Spin polarized transport; Spin torque
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2009.06.048

Domain walls (DWs) propagated along nanoscale magnetic wires by current or field pulses could potentially be used for data storage or logic applications, but the understanding of the DW dynamics, particularly under the influence of spin-polarized current, is incomplete. Measuring the velocity can give insights into the physics of the DW motion. Here we demonstrate DW velocity measurements in permalloy ( Ni 80 Fe 20 ) nanowires (1500 nm width and 20 nm thickness) using the techniques of X-ray magnetic circular dichroism photoemission electron microscopy (XMCD-PEEM) to image the magnetic contrast in the nanowires, and single shot Kerr microscopy, which allows for dynamic measurements. The magnetic imaging yields the average velocity as well as information on the DW spin structure, whereas the single shot method highlights the stochastic nature of the DW motion.