Read and write characteristics of Co-Ni-Zr-M/Cr thin films for longitudinal recording

The magnetic and crystallographic properties and read and write characteristics of sputtered C/Co-Ni-Zr/Cr and C/Co-Ni-Zr-M/Cr (M=V, Nb, Ta, Cr, Mo, W, Cu, Si, Al, Ru and Pt) thin films are investigated. The saturation magnetic flux density B/sub s/ of all C/Co-Ni-Zr-M/Cr films decreases as the amount of additive element increases. The coercivity of C/Co-Ni-Zr-Cr/Cr and C/Co-Ni-Zr-Pt/Cr is higher than that of C/Co-Ni-Zr/Cr films with comparable B/sub s/. The larger the perpendicular anisotropy K/sub p/ and the smaller the anisotropy constant K/sub n/, the lower the media noise N and the higher the S/N ratio. The reduction of K/sub n/ and N are strongly connected to grain separation and grain size reduction. The larger the B/sub s/.tmag, the higher E/sub II/ and N and the lower D/sub 50/ and the S/N ratio. All films except those with Si, Ru, and Pt additives have large K/sub p/, a small K/sub n/, and a high S/N ratio. In particular, C/Co-Ni-Zr-M/Cr (M=Cr, Mo, W, and Al) disks have a better S/N ratio and D/sub 50/ than C/Co-Ni-Zr/Cr disks.<
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