Iv. Roshchin et al., Magnetic properties of Fe microstructures with focused ion beam-fabricatednano-constrictions, IEEE MAGNET, 37(4), 2001, pp. 2101-2103
Studies of the magnetic properties of Fe microfabricated wires with a mecha
nically stable 40 to 120 nm-wide constriction produced with focused ion bea
m are reported. The 2 to 20 mum-wide, wires are fabricated by photolithogra
phy from 3 nm and 25 nm-thick epitaxial (110) bcc Fe films. This fabricatio
n method appears to preserve the magnetic properties of the constriction. T
he structures are studied by MFM and by magneto-optic Kerr effect (MOKE) me
asurements. The ratio of the wire linewidth to its thickness determines the
demagnetization factor and, therefore, influences the coercivity of the wi
re. Both a step in the width of the wire and a nano-constriction in the mid
dle of the wire are found to be domain wall (DW) pinning centers.