COMPARISON OF TIME-DECAY OF READ-BACK SIGNALS IN KEEPERED AND NON-KEEPERED MEDIA

Soft sendust keeper layer has been sputtered on top of longitudinal th in film media which has an M(r)t value of 0.49 memu/cm(2). Measurement s of time-decay in both keepered anti non-keepered longitudinal thin f ilm media have been performed on a spin-stand tester. Experimental res ults showed that time-decay is larger in tested media which has lower M(r)t values compared to those that have a larger M(r)t of 1.26 memu/c m(2). A 50 Angstrom thick sendust keepered media has about half the de cay rate compared to its non-keepered counterpart (M(r)t =0.49 memu/cm 2) at a recording density of 6000 fr/mm. Also, it was found that time- decay in 100 Angstrom and 150 Angstrom thick keepered media is less th an that in a 50 Angstrom keeper media.