Playback Performance of Facing Targets Sputtered Tape Media on Moving Tape Substrate with a High Speed

Playback performances and microstructures of facing targets sputtered (FTS) longitudinal recording tape media on moving tape substrates were investigated at a fast (100 cm/min) and a slow (5.8 cm/min) moving speed. CoPtCr-SiO₂ granular magnetic layers were deposited on Ru underlayer on moving 4.5 mum thick Aramid films by a FTS system at room temperature. Coercivity over 300 kA/m and grain structures with average diameter of 8 nm were achieved on very thin plastic film. Moving speed does not affect microstructure grown by FTS. The magnetic grains are physically isolated by segregation of silicon and chromium to grain boundaries. This was observed by transmission electron microscopy (TEM) and spot energy-dispersive X-ray spectroscopy (EDS). Cross-sectional TEM images show that straight columnar magnetic grains were grown and unaffected by the moving direction of the substrate. In playback tests, it was shown that both samples had over 8 dB higher SNR than commercial particulate tape media of 0.5 Gb/in ² areal density.