Structural, magnetic and recording properties of CoCrTa/Co₃ O₄/Pt perpendicular thin films media

This paper reports an investigation of the structural, magnetic and recording properties of a tri-layer Co₈₀Cr₁₆Ta ₄ (2000 Å)/Co₃O₄ (50 Å)/Pt (100 Å) magnetic thin film. Compared with CoCrTa glass, 50 Å Co₃O₄ and 100 Å Pt, CoCrTa deposited on the composite Co₃O₄ (50 Å)/Pt (100 Å) underlayer exhibits strong perpendicular hcp (00.2) crystalline orientation with Δθ₅₀~ 4.1°, fine grains with sub-grain features ~10-40 nm, small S_|| ~13%, large room-temperature Hc _⊥~1650 Oe, large R (the ratio between Hc_⊥ Hc_||)~6, and a sharp Hn_⊥ (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 D₅₀ of ~4500 fr/mm and noise behavior characteristic of a perpendicular medium