Feasibility of FePt longitudinal recording media for ultrahigh density recording

Abstract

The feasibility of chemically ordered, ultrathin FePt longitudinal media for ultrahigh recording density is discussed with the basic magnetic and structural properties which can be obtained under acceptable thin film processing condition, as well as preliminary read/write test. High coercivity (≫3000 Oe) could be achieved even in the film with very low Mrt (≪0.3 memu/cm2) at moderate annealing temperature (375–450 °C). However, rapid degradation of crystallographic texture with thickness, in the absence of proper template layer, results in very low coercivity squareness (S*∼0.2), which may be detrimental to recording application. Media noise, particularly exchange coupling induced transition noise, may not be a critical problem, by virtue of extremely small grain size (≃5 nm) and high Ku.