Microscopic magnetic relaxation processes in epitaxial Fe/GaAs(001) mesostructures

The magnetic relaxation and domain processes in epitaxial Fe/GaAs(0 0 1). t hin films and square dots have been investigated using time-resolved scanni ng Kerr microscopy. For 55 and 250 Angstrom Fe/GaAs(0 0 1) continuous films , it is clearly seen that relaxation proceeds by both discontinuous and sin gle 'jumps'. Magnetic relaxation studies reveal that large and abrupt wall displacements occur for the magnetisation reversal in 300 Angstrom epitaxia l Fe/GaAs(0 0 1) square dots, regardless of dot size (w = 5-45 mum). Domain observations demonstrate that domain wall motion dominates the magnetisati on reversal in the dot structures in spite of the presence of the dot edges . (C) 2001 Published by Elsevier Science B.V.