Measurement of the attempt frequency in antiferromagnets

Abstract

The characteristic relaxation frequency of a granular antiferromagnet f0 in the Ńel-Arrhenius expression has been calculated from a high resolution measurement of the time dependence of the median blocking temperature of a CoFe/IrMn exchange biased system. Calculations based on a granular model give f0 = (2.1±0.4) × 1012 s-1, three orders of magnitude greater than values commonly found in the literature. © 2010 American Institute of Physics.