Hyperfine FePt patterned media for terabit data storage

FePt patterned media were fabricated with varying pattern size, employing a deposition-last process and a CrV seed layer. The FePt patterns of sizes down to 30 nm showed a well-developed FCT structure characteristic of L10 phase. Due to the chemical and structural ordering, even 30 nm-sized FePt patterns exhibited a high ratio (3.4) of out-of-plane coercivity to in-plane coercivity and almost the same remanent magnetization as the saturation magnetization, indicating that a high perpendicular anisotropy is retained in the tiny patterns. The array of 30 nm patterns corresponds to a bit density of 1.8 Tbit/in2, demonstrating that terabit-density magnetic storage can be fabricated using the deposition-last process.