Exchange-coupled IrMn/CoZrNb soft underlayers for perpendicular recording media

An antiferromagnetic Ir-Mn pinning layer was applied to reduce the spike noise that originates from domain walls in a Co-Zr-Nb soft magnetic layer of perpendicular recording media. Blocking temperature was 285/spl deg/C and exchange-coupling energy of 0.22 erg/cm/sup 2/ was obtained by arranging a Co-Fe layer between Ir-Mn and Co-Zr-Nb films, without any thermal treatments to enhance the exchange-coupling field. Spike noise was successfully reduced over the entire disk area using a rapid thermal annealing process, and the total amount of noise generated from a soft magnetic layer decreased as the exchange bias field increased.