Diluted antiferromagnet effect on magnetic and microwave characteristics of exchange-biased multilayered thin films

Abstract

A comprehensive experimental study of the effect of antiferromagnetic (AF) dilution on the magnetic properties and microwave characteristics of Fe 70Co 30/(Mn 75Ir 25) 1-x(Al 2O 3) x multilayered thin films with the variation of AF thickness was performed. Our result reveals a linear relationship between the critical AF thickness and the dilution of the AF layers providing an evidence of a volume effect in the AF layers consistent with the domain state model. The AF magnetic anisotropy deduced from the critical AF thickness was found to reduce monotonically with the AF dilution. The variations of exchange bias, rotational magnetic anisotropy, ferromagnetic resonance frequency, and effective damping factor with the AF dilution and thickness have also been presented and discussed. © 2012 American Institute of Physics.