K. Takano et al., RESOLUTION OF UNSHIELDED AND SHIELDED MR HEADS FOR PERPENDICULAR MAGNETIC RECORDING, Journal of magnetism and magnetic materials, 176(1), 1997, pp. 61-65
To achieve the recording technology over 10 Gb/in(2), quite short bit
cells have to be written and read probably by an MR head. The resoluti
ons of unshielded and shielded MR heads were estimated for perpendicul
ar and longitudinal recording. Moreover, we designed and fabricated so
me samples of the MR/Inductive heads that have been developed for perp
endicular magnetic recording, and evaluated them with a double-layered
medium. The shielded MR head offered high D-50 of 170 kFRPI and high-
density readback signal of 500 kFRPI. However, when the recorded bit l
ength became shorter than the MR-to-shield gap, the shield had little
effect and the output of the shielded head was no longer roughly equal
to that of the unshielded head. Even unshielded MR head has good high
-density recording characteristics in case of the combination with a p
erpendicular medium.