FePt-C graded media for ultra-high density magnetic recording

Tri-layer FePt-C graded media composed of three FePt-C layers with each single FePt-C layer deposited at different substrate temperatures were fabricated. The single hard layer FePt-C had a large coercivity of 11.4 kOe, while the coercivity of the tri-layer sample was only 5.7 kOe. A coercivity reduction factor of 2 was achieved without sacrificing the thermal stability of the media. The tri-layer media revealed incoherent magnetization switching-domain wall propagation. The microstructure showed that the tri-layer FePt-C graded media were graded media combined with modified coupled granular continuous (CGC) media. This new kind of graded media had a lower switching field and comparable thermal stability and should have the advantage of CGC media-lower transition noise.