Micromagnetic and experimental studies of CoPtCr polycrystalline thin film media with bicrystal microstructure

Polycrystalline CoPtCr/CrV (or Cr) thin films with different Cr concentrations were prepared by sputter deposition on NiP-plated Al substrates. TEM images revealed the existence of bicrystal clusters. High field torque measurement was used to determine the intrinsic anisotropy constant. The M-H loop and torque hysteresis measurement coupled with micromagnetic modeling permitted determination of intergranular interactions. The cross-track correlation length was evaluated from micromagnetic noise calculation and compared well with the result from measured noise spectra. The physical implication of a bicrystal structure is discussed in general.