Visualization of the Barkhausen effect by magnetic force microscopy.
By visualization of the Barkhausen effect using magnetic force microscopy we are able to provide detailed information about the physical principles that govern the magnetization reversal of a granular ferromagnetic thin film with perpendicular anisotropy. Individual Barkhausen volumes are localized and distinguished as either newly nucleated or grown by domain wall propagation. The Gaussian size distribution of nucleated Barkhausen volumes indicates an uncorrelated random process, while grown Barkhausen volumes exhibit an inverse power law distribution, which points towards a critical behavior during domain wall motion.
Institute of Applied Physics, University of Hamburg, Jungiusstrasse 11, 20355 Hamburg, Germany. aschwarz@physnet.uni-hamburg.de
Alexander
A
Schwarz
Marcus
M
Liebmann
Uwe
U
Kaiser
Roland
R
Wiesendanger
Tae Won
TW
Noh
Dong Wook
DW
Kim