Feasibility of FePt longitudinal recording media for ultrahigh density recording

The feasibility of chemically ordered, ultrathin FePt longitudinal media fo r ultrahigh recording density is discussed with the basic magnetic and stru ctural properties which can be obtained under acceptable thin film processi ng condition, as well as preliminary read/write test. High coercivity (>>30 00 Oe) could be achieved even in the film with very low M-rt (<<0.3 memu/cm (2)) at moderate annealing temperature (375-450 degrees C). However, rapid degradation of crystallographic texture with thickness, in the absence of p roper template layer, results in very low coercivity squareness (S*similar to 0.2), which may be detrimental to recording application. Media noise, pa rticularly exchange coupling induced transition noise, may not be a critica l problem, by virtue of extremely small grain size (similar or equal to 5 n m) and high K-u. (C) 2000 American Institute of Physics. [S0021- 8979(00)46 708-3].