Hiroaki Ono

Study on requirements for shielded current perpendicular to the plane spin valve heads based on dynamic read tests

Shielded current perpendicular to the plane (CPP) spin valve heads with about 20 Gbit/in.2 dimensions were fabricated and tested both quasistatically and dynamically. Dual synthetic spin valves with 2.3 mΩu200aμm2 of resistivity change and area product (dRA) was used. Quasistatic tests were conducted to determine the current efficiency loss caused by the specific CPP head structure. Dynamic tests were performed to examine the flux efficiency of the readback process in the spin valve element, in order to confirm the calculation results which take into account the increase of effective anisotropy field caused by the circular sense current field. Output voltage of about 260 μV (peak to peak) was successfully obtained from the dynamic tests. Finite element modeling analysis of current distribution and temperature rise, together with degradation experiments with excessive sense current, was conducted to predict the maximum allowable current density in the 200 Gbit/in.2 dimension, where read track width and stripe ...

Investigation of Higher Recording Density Using an Improved Co–CoO Metal Evaporated Tape With a GMR Reproducing Head

To demonstrate the highest areal recording density of tape media, we have developed a metal evaporated tape with higher magnetic anisotropy of 2.5times10⁵ J/m³ and finer magnetic activation volume of 2.7times10^-24 m³ of a Co-CoO recording layer deposited on a smoother base film. A capability of an areal recording density of 23.0 Gb/in² was confirmed using a giant magnetoresistive head as a read head. The smoother surface roughness improved signal-to-noise ratio more than 2 dB

Effect of surface resisitance of metal evaporated tape on discharging current

In this paper, we obtain higher recording density, a GMR head would be used. This head is more sensitive to ESD current than the AMR head. We found that the higher surface resistance of ME tape was effective in reducing the discharging current through the MR head.

Study of Perpendicular AME Media in a Linear Tape Drive

The magnetic recording performance of perpendicularly oriented advanced metal evaporated (AME) media is studied in a linear tape drive. A modified evaporation process produces the perpendicular orientation, which substantially reduces the writing asymmetry of obliquely oriented AME media in a linear recording environment. While the read back signal exhibits characteristics of perpendicular media, the timing-based servo signal in the drive enables track-following performance with a 1 sigma position error signal (PES) of 0.2 mum . The read channel correctable error rate at the LTO Gen 4 operating point is 10-6 in both the forward and backward directions and the durability of the tape exceeds 100 000 passes without signal degradation.