Measurement of the anisotropy constant of antiferromagnets in metallic polycrystalline exchange biased systems

Gonzalo Vallejo Fernandez, L.E. Fernandez-Outon, K. O'Grady

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A method for the measurement of the anisotropy constant of the antiferromagnet (AF) K-AF in exchange biased systems has been developed. This has been achieved by measurement of the median blocking temperature < T-B > of a CoFe/IrMn bilayer. In thermal activation-free conditions, this is the temperature at which equal volumes of the AF are oriented in opposite senses. Hence, for a grain size dependent model, the critical volume for thermal activation at this point is equal to the median volume of the grain size distribution. A value of (5.5 +/- 0.5)x10(6) erg/cc has been obtained at room temperature for a 4 nm thick IrMn layer. (C) 2007 American Institute of Physics.

Original languageEnglish
Article number212503
Number of pages3
JournalApplied Physics Letters
Issue number21
Publication statusPublished - 19 Nov 2007



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