Consequences of line defects on the magnetic structure of high anisotropy films: Pinning centers on

Institute of Applied Physics and Microstructure Research Center University of Hamburg - Jungiusstrasse 11, D-20355 Hamburg, Germany

Received: 28 August 2006
Accepted: 18 September 2006

Abstract

The narrow domain wall width w of high-anisotropy materials induces significant pinning of magnetic domains at line defects which —due to spatial resolution limitations— could not be studied directly in the past. By means of spin-polarized scanning tunneling microscopy we have directly correlated the morphology and domain structure of ferromagnetic Dy/W(110) on the nanometer scale. Indeed, the images reveal an effective pinning of the domain walls by two types of line defects. They are identified by growth studies and atomic resolution STM as screw and edge dislocations, two fundamental lattice distortions in solid-state physics.