Comparison of Playback Performance of Facing Targets Sputtered Perpendicular and Longitudinal Tape Media

Abstract

Playback performances of sputtered perpendicular recording tape media were investigated in comparison with longitudinal media. Perpendicular (Media P, out-of-plane coercivity of 318.3 kA/m) and longitudinal (Media L, inplane coercivity of 279.3 kA/m) recording tape media were deposited by facing targets sputtering from the same target of Co <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">74</sub> Pt <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">16</sub> Cr <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> -SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> for the recording layer at room temperature. For Media P, a soft magnetic FeCoB(50 nm) layer and a Ru(5 nm) seed layer were formed between the recording layer and an Aramid substrate. On the playback test by a drum tester with a ring writer/GMR reader, the waveform of all-ones signal at 5 kfci indicates that Media P has a dipulse response and the shorter PW50 value than Media L. Measured values of D50 were 233 kfci for Media P and 216 kfci for Media L, respectively. Saturation curves show that Media P has good writability. The signal-to-noise ratio (SNR) value of Media P is higher by 2.4 dB at 337 kfci than Media L. These high-resolution and high SNR properties indicate that sputtered perpendicular tape media are suitable for extremely high-density recording.