Study of bit-patterned FePt media for high density magnetic recording

Abstract

A combination of heat assisted magnetic recording and bit patterned media has been envisaged to extend the areal density in hard disk drives beyond 1Tb/in². In this thesis, the factors affecting self-assembly as a high density and large area nano-patterning technique on various kinds of surfaces have been established. Self-assembly of polystyrene-b-polydimethylsiloxane (PS-b-PDMS) on surfaces with roughnesses varying at angstrom-scale was carried out. The study revealed that for the attainment of self-assembly on magnetic media surfaces, a stringent control over the surface roughness is crucial. In addition, fabrication of high anisotropy and smaller-sized L1₀ FePt magnetic grains without spacer materials has been studied. Structural disorder induced in FePt films by low energy C⁺ ion embedding has also been investigated. A novel scheme has been developed for achieving bit patterned FePt media by creating alternate magnetic and non-magnetic regions using large area self-assembly and low energy ion bombardment.