Abstract
The laminated soft layer (LSL) Pt/CoPtCr-SiO 25 was used in exchange coupled composite (ECC) media and exhibited a tunable perpendicular anisotropy by changing the thickness of Pt. By using x-ray magnetic circular dichroism, the incoherent reversal in the ECC media with a LSL was directly observed. The nucleation field of ECC media was found to be dominated by the anisotropy of the LSL. The increased thickness of the Pt layers in the LSL reduced the anisotropy, which promoted incoherent reversal; however, with the Pt thickness increasing larger than 0.9 nm, the interlayer coupling between the LSL and the hard layer was significantly reduced, and thus the assisting effect was suppressed. Furthermore, the dependence of remanent coercivity H cr on the Pt thickness confirmed that the assisting effect can be optimized by controlling the Pt thickness to balance the LSL anisotropy and the interlayer coupling. © 2011 American Institute of Physics.