TiN and TiC interlayers for FePt-C based magnetic recording media

Conductive TiN and TiC interlayers were utilized to promote epitaxial growth of (001)-textured FePt in place of the traditional non-conductive MgO interlayer. The film structure was given as Glass/CrRu/(TiC or TiN)/FePt-C. The films were fabricated under constant deposition temperature of 350°C for all three layers. Both TiN and TiC were capable of inducing (001)-textured FePt with square magnetic hysteresis loops and out-of-plane coercivity of up to 4kOe. Further increase in FePt recording layer deposition temperature to 500°C resulted in monotonic increase in coercivity of up to 9kOe whilst still maintaining strong perpendicular anisotropy, large magnetic squareness, and a small in-plane component. Subsequent doping of up to 40 vol. % C in FePt led to further increases in coercivity beyond 15kOe together with reduction in intergranular lateral exchange coupling.