Title :
Rigid disk medium for 20 Gb/in2 recording demonstration
Author :
Sato, Kenji ; Yoshida, Yuki ; Yamagishi, Michinaga ; Ueno, Hiroaki ; Akimoto, Hideyuki ; Abarra, E. Mohan ; Kanai, Hitoshi ; Uehara, Yuji ; Okamoto, Iwao ; Uematsu, Yukihiro
Author_Institution :
File Memory Lab., Fujitsu Labs. Ltd., Atsugi, Japan
fDate :
9/1/1999 12:00:00 AM
Abstract :
A longitudinal medium was developed for 20 Gb/in2 recording. This medium has a coercivity of 3380 Oe and Mrδ=0.42 memu/cm2. Modulation noise and track edge noise were well suppressed by the decrease in the activation volume. Remanent magnetization is stable; at 338 K, the coefficient of remanence reduction was -0.066 dB/decade in a reverse field of 460 Oe which corresponds to the demagnetizing field in a bit at 430 kFCI. Recording bits of 430 kfci were confirmed by MFM. The BER was 3.45×10-6 using a conventional EPR4 channel with a 16/17 code rate at 405 kBPI (430 kFCI). From squeeze measurements, the track pitch was 0.505 μm (50.3 ktpi) including a guard band of 0.06 μm. 20.4 Gb/in2 recording is made possible by the combination of a narrow gap spin-valve head and a low noise medium
Keywords :
coercive force; demagnetisation; hard discs; magnetic recording noise; magnetisation; remanence; 16/17 code; BER; EPR4 channel; activation volume; coercivity; demagnetizing field; longitudinal recording; modulation noise; narrow pole tip write head; remanent magnetization; rigid disk; spin valve read head; thermal stability; track edge noise; Bit error rate; Coercive force; Demagnetization; Disk recording; Magnetic field measurement; Magnetic force microscopy; Magnetic heads; Magnetization; Noise measurement; Remanence;
Journal_Title :
Magnetics, IEEE Transactions on
