EFFECTS OF INTER-LAYER MAGNETIC-INTERACTIONS IN MULTILAYERED COCRTA/CR THIN-FILM MEDIA

The magnetic properties and media noise of double-magnetic-layer longitudinal CoCrTa/Cr thin film media were investigated as a function of the Cr separation layer thickness. It is found that the media noise power decreases rapidly for initial increase of Cr separation layer thickness (10 angstrom approximately 25 angstrom) and gradually increases for further increase of Cr spacer thickness(25 angstrom approximately 300 angstrom). The highest signal-to-noise ratio (SNR) improvement obtained was 5.5dB for a double magnetic layer film with 25 angstrom Cr separation rather than the expected 3dB for the film with thicker Cr separation. The remanent magnetization delta-M-curves vs. applied field are utilized to study the magnetic interactions between the two magnetic layers. The results indicate that 25 angstrom Cr separation layer is adequate to decouple the two magnetic layers from exchange coupling, and the magnetostatic inter-actions between two magnetic layers can alter the effects of the magnetic interactions inside the magnetic layers so as to further reducing the media noise.