  We report on the investigation of coercivity changes of the
Co$_{72}$Pt$_{28}$/Co$_{81}$Ir$_{19}$ exchange-coupled composite (ECC) media
with negative soft-layer (SL) magnetocrystalline anisotropy (MA) . Our results
show that the hard-layer (HL) of our sample exhibits a columnar type
microstructure with well isolated grains and the SL with hcp-structure grows on
top of the HL with the same texture. Therefore, strong coupling of the two
layers have been realized as evidenced by the magnetic characterization.
Importantly, we observe a more effective reduction of the coercivity of the ECC
media by using SLs with negative MA when compared to the use of SLs with
positive or negligible MA. The experimental results are corroborated by
theoretical calculations.
