Preparation and Read/Write Characteristics of Co-γFe₂O₃/NiO Longitudinal Magnetic Recording Media

Abstract

Co-γFe₂O₃ longitudinal magnetic recording media obtained by annealing CoO-Fe₃O₄ were prepared on NiO underlayer. The coercivity H_c was varied with the Co content, namely, the atomic ratio of Co/Fe in Co-γFe₂O₃, and the oxygen partial pressure in deposition of CoO-Fe₃O₄. The H_c of the media with Co/Fe = 4 at% was 2000-3500 Oe, 1.3-3.6 times higher than that of Co-γFe₂O₃ media without NiO underlayer. The grain size of Co-γFe₂O₃ became smaller with decreasing the thickness. The read/write characteristics of the media with no overcoat were evaluated in contact recording. Co-γFe₂O₃ media on NiO had higher D₅₀ and lower medium noise than those of the media without NiO underlayer.