Measurement of magnetic domain wall width using energy-filtered Fresnel images.
Magnetic domain walls in Nd2Fe14B have been examined using a series of energy-filtered Fresnel images in the field emission gun transmission electron microscope (FEGTEM). We describe the changes in the intensity distribution of the convergent wall image as a function of defocus, foil thickness and domain wall width. The effect of tilted domain walls and beam convergence on the fringe pattern is also discussed. A comparison of the experimental intensity profile with that from simulations allows the domain wall width to be determined. Measurement of very narrow walls is made possible only by using a relatively thick foil, which necessitates energy-filtering to allow quantitative comparison with simulations. The magnetic domain wall width in Nd2Fe14B was found to be 3 +/- 2 nm.
Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ, UK. SJL16@cus.cam.ac.uk
S J
SJ
Lloyd
J C
JC
Loudon
P A
PA
Midgley