MAGNETIC, RECORDING, AND CRYSTALLINE PROPERTIES OF MULTILAYERED LONGITUDINAL THIN-FILM MEDIA

Multilayered longitudinal CoCrTa and CoCrPt media were evaluated for magnetic and recording properties. Depending on the alloy, multilayering produced 150-500 Oe increases in coercivity over equivalent single-layer media. These coercivity increases were also found to depend on the chromium underlayer and spacer layer thickness. The coercive squareness of the CoCrPt media was found to decrease upon multilayering, while S* of the CoCrTa double layer showed a slight increase with thicker Cr spacer layers. Double layering of the CoCrPt alloy produced up to a 4-dB increase in signal-to-noise ratio, while double-layer CoCrTa media demonstrated a 2.7-dB increase. Differences between the magnetic and recording properties of CoCrPt multilayers deposited on Cr underlayers of varying thicknesses are analyzed in terms of changes in crystalline anisotropy introduced by the multilayering process.