Fabrication of perpendicular magnetic recording tape media with a data capacity of over-50TB using Si/NiFe/FeCoB soft magnetic underlayers

C-axis orientations of Ru intermediate layer (IML) and CoPtCr-SiO2 recording layer (RL) are attained by using crystalline FeCoB soft magnetic underlayer (SUL). Better (110) orientation of FeCo improves not only (001) orientation of Ru IML but also that of CoPtCr RL. This leads better perpendicular magnetic anisotropy in the RL suitable for perpendicular magnetic recording media. In order to control the (110) orientation in FeCoB layer, various seed layers are prepared beneath the FeCoB layers. Ru and Si/NiFe seed layers gives FeCoB layer a large in-plane magnetic anisotropy that is effective to suppress spike noise from SUL. The laminated FeCoB SUL causes more improvement of Ru (001) texure and leads to better perpendicular magnetic anisotropy of RL. Ru/CoPtCr-SiO2 bilayer deposited on laminated FeCoB SUL on Aramid tape substrate has good perpendicular magnetic properties and reduces the noise from SUL. PACS: Type pacs here, separated by semicolons;