Measurement Of The Attempt Frequency In Antiferromagnets

The characteristic relaxation frequency of a granular antiferromagnet f(0) in the Neel-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 f(0) = (2.1 +/- 0.4) x 10(12) s(-1), three orders of magnitude greater than values commonly found in the literature. (C) 2010 American Institute of Physics. [doi:10.1063/1.3522887]