Structural, magnetic and recording properties of CoCrTa/Co/sub 3/O/sub 4//Pt perpendicular thin films media

This paper reports an investigation of the structural, magnetic and recording properties of a tri-layer Co/sub 80/Cr/sub 16/Ta/sub 4/ (2000 /spl Aring/)/Co/sub 3/O/sub 4/ (50 /spl Aring/)/Pt (100 /spl Aring/) magnetic thin film. Compared with CoCrTa glass, 50 /spl Aring/ Co/sub 3/O/sub 4/ and 100 /spl Aring/ Pt, CoCrTa deposited on the composite Co/sub 3/O/sub 4/ (50 /spl Aring/)/Pt (100 /spl Aring/) underlayer exhibits strong perpendicular hcp (00.2) crystalline orientation with /spl Delta//spl theta//sub 50//spl sim/ 4.1/spl deg/, fine grains with sub-grain features /spl sim/10-40 nm, small S/sub /spl par// /spl sim/13%, large room-temperature Hc /sub /spl perp///spl sim/1650 Oe, large R (the ratio between Hc/sub /spl perp// Hc/sub /spl par//)/spl sim/6, and a sharp Hn/sub /spl perp// (perpendicular nucleation field) distribution. Recording measurements performed on the tri-layer film using a thin film tri-pad head showed a pronounced isolated di-pulse in the reproduced waveform, a D/sub 50/ of /spl sim/4500 fr/mm and noise behavior characteristic of a perpendicular medium.