Kochan Ju

Low Fringe-Field And Narrow-Track MR Heads

The ABS focused ion beam technique was utilized to pattern MR heads into different geometry at track edges to study side-writing performance. By spinstand testing, both written track width and erase distance were measured. An analytical model was developed to analyze the dependence of the side-writing on the etching step length. Effects of the etching width, which affects the total etching time, were also studied.

5 Gb/in/sup 2/ recording with dual stripe AMR heads and low noise thin film disks

We have demonstrated magnetic recording at an areal density of 5 Gb/in/sup 2/ using dual stripe magnetoresistive heads (DSMR) on low noise and low-glide height quaternary CoCrTa-based alloy thin film disks. The data rate is 120 Mb/sec with a PR4 channel, and the on-track error rate achieved is around 10/sup -9/. The demonstration was accomplished in two cases using two different types of heads. In the first case, it was done with a DSMR head having shield-shield spacing of 0.165 /spl mu/m and 1 /spl mu/m stripe height flying at 25 nm, resulting in a linear density of 321.7 KBPI, and a track density of 15.6 KTPI. The second case was performed with DSMR heads having shield-shield spacing of 0.18 /spl mu/m and 8 /spl mu/m stripe height flying at proximity height of 12 nm, achieving a 358.75 KBPI and 13.8 KTPI. This is the highest linear density published so far for either GMR or AMR heads. It is the direct consequence of high signal/noise of DSMR heads and proximity recording over low noise, low-glide-height media. To explore the large dynamic range of DSMR heads, this study was also done with a variety of low noise disks with Mrt ranging broadly from 0.45 to 1.0 memu/cm/sup 2/ and coercivity of 3000 Oe.

10 Gb/in/sup 2/ recording with DSMR AMR heads on low noise thin film disks

Areal density of 5 Gb/inz with AMR SAL was demonstrated[l] in the past, and more recently, with DSMR heads 121. Areal density of more than 10 Gb/in* with spin valve heads has been reported this yeafl5,SJ. However, in these demonstrations, there appears to have some practical weaknesses which make them unattractive for immediate practical applications. The details for the above spin valve heads has yet to be published but in one case [6]. using FIB write heads together with spin valve read heads is not yet practical. Here we will report 10 Gb/inz demonstration using dual stripe magneto-resistive heads [DSMR] with the current manufacturing process.