News from Nanotechjapan


Areal Density in Magnetic Tape Recording Improved over 20 Times

 Sony Corporation announced on 2 August 2017 that, in collaboration with IBM Research - Zurich, Sony had developed magnetic tape technology to enable over 20 times improvement in recording areal density demonstrating 201 Gbit/inch2 on sputtered magnetic tape. IBM also released this achievement and science portal site also reported the news. Details were disclosed at The 28th Magnetic Recording Conference(TMRC 2017)*.

 Magnetic tape systems are currently reviving as the most cost effective solution for the storage of large volumes of infrequently accessed data. The technical level of the areal density of commercial linear-tape drives remains at 5-7 Gb/in2, and its scale-up has been continually demanded. The research group has responded to the requirement by developing a perpendicularly oriented sputtered tape technology in place of the conventional barium ferrite (BaFe) coating.

 The sputtered tape media is composed of the following layers: a diamond-like carbon (DLC) overcoat (5 nm), a CoPtCr-SiO2 magnetic layer (14 nm), a Ru intermediate layer consisting of two films formed under different sputtering conditions (#1:18 nm/#2:5 nm), NiW (10 nm)/TiCr (2 nm) seed layers, and a CoZrNb (14 nm) soft under-layer deposited onto a polyaramide substrate. In addition to the resulting low surface roughness of 0.9 nm, a novel low friction tape head technology with a new lubricant achieved very smooth tape movement.

 Combined with newly developed innovative signal processing algorithm and advanced servo control with an accuracy of better than 7 nm for 48 nm wide tunneling-magnetoresistive (TMR) hard disk drive read head, a prototype sputtered magnetic tape demonstrated a single-channel tape areal density of 201 Gb/in2. Twenty times improvement in recording density will compensate the increased cost of sputtering against coating.

*Simeon Furrer, Mark A. Lantz, Peter Reininger, Angeliki Pantazi, Hugo E. Rothuizen, Roy D. Cideciyan, Giovanni Cherubini, Walter Haeberle, Evangelos Eleftheriou, Junichi Tachibana, Noboru Sekiguchi, Takashi Aizawa, Tetsuo Endo, Tomoe Ozaki, Teruo Sai, Ryoichi Hiratsuka,  Satoshi  Mitamura, and Atsushi Yamaguchi, "201 Gb/in2 Recording Areal Density on Sputtered Magnetic Tape", The 28th Magnetic Recording Conference(TMRC 2017), Session BP HAMR & Systems Contributed Posters, Paper No. BP-02, Presented on 2 August 2 2017; Publication of Summary: 19 July 2017, to be published in IEEE Transactions on Magnetics ; DOI: 10.1109/TMAG.2017.2727822