title: Runaway "fingerlike" instability of magnetic walls in ultrathin layers.
abstract: We show that smooth domain walls in ultrathin ferromagnetic films can develop jaggedness even in the absence of random defects when confronted with a sufficiently large tilt between the uniaxial anisotropy direction and the external field. From the Kerr imaging of 0.7 nm thin Co films and from numerical simulations we report a previously unseen runaway fingerlike instability in a magnetic wall that begins on nanoscales but grows to macroscopic lengths for sufficiently large tilt angles. A threshold for the instability is controlled by the ferromagnet's parameters and the applied field.
authors.affiliation: IBM Research Division, T. J. Watson Research Center, Yorktown Heights, New York 10598, USA.
authors.forename: B G
authors.initials: BG
authors.lastname: Elmegreen
authors.forename: L
authors.initials: L
authors.lastname: Krusin-Elbaum
authors.forename: T
authors.initials: T
authors.lastname: Shibauchi
authors.forename: B
authors.initials: B
authors.lastname: Argyle