Magnetisation reversal in cobalt and permalloy nano-elements

Kirk, K.J., Chapman, J.N., Aitchison, P., McVitie, S. , Khamsehpour, B., Ruhrig, M. and Wilkinson, C.D.W. (1997) Magnetisation reversal in cobalt and permalloy nano-elements. In: Hadjinpanayis, G.C. (ed.) Magnetic hysteresis in novel magnetic materials. Series: NATO ASI series. Series E, Applied sciences (338). Kluwer Academic Publishers: Dordrecht ; Boston, pp. 309-313. ISBN 9780792346043 (doi: 10.1007/978-94-011-5478-9_29)

Abstract

We have investigated the domain structure and reversal mechanism in sub-micron sized magnetic elements using Lorentz microscopy in a transmission electron microscope (TEM). Acicular nano-elements were fabricated from thin films of Co and permalloy (NiFe) using electron beam lithography and lift-off techniques. The elements were 200 nm wide, 1.6-2.6 mu m long and 20-50 nm thick, with their ends either flat (rectangular) or pointed (triangular). Fresnel and Foucault techniques were used to image the domain structure in the elements in order to measure the switching fields and observe the reversal mechanisms. It was found that the magnetic properties depended strongly on the material, element width and film thickness, and on certain aspects of their shape. In particular the presence of two pointed ends greatly increased the switching field.

• Item Type: Book Sections
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: McVitie, Professor Stephen and Chapman, Professor John and Wilkinson, Professor Christopher and Kirk, Dr Katherine
• Authors: Kirk, K.J., Chapman, J.N., Aitchison, P., McVitie, S., Khamsehpour, B., Ruhrig, M., and Wilkinson, C.D.W.
• College/School: College of Science and Engineering; College of Science and Engineering > School of Physics and Astronomy
• Publisher: Kluwer Academic Publishers
• ISSN: 0168-132X
• ISBN: 9780792346043