High Recording Density Tape Using Fine Barium-Ferrite Particles With Improved Thermal Stability

The effects of reducing barium-ferrite magnetic particle volume have been studied. We optimized barium-ferrite substitution elements and their amount and demonstrated thermal stability for very fine particles of the size 1.5 × 10
³
nm
³
. Using a giant magnetoresistive (GMR) head with a 0.2 ¿m read track width, test tape containing these fine particles exhibited a bit error rate of 1.5 ×10
^-4
at a linear density of 360 kbpi using a noise predictive maximum likelihood (NPML) detection for nonstationary noise sources, i.e., data-dependent noise. This corresponds to a 15 Gb/in
²
areal recording density in linear tape application.