On the resolution of perpendicular magnetic head

The wavelength response of a reproducing head can be estimated quantitatively by the superposition of isolated pulses in perpendicular magnetic recording, because recording demagnetization does not occur. In this paper, the resolution of reproduction of a single-pole head is theoretically investigated for various thicknesses of the main-pole and compared with the experimental results. It is also shown that the 50 % down density D50is influenced by the virtual spacing, which depends on the thickness of the Co-Cr layer of a double-layered medium. To realize the high resolution of a single-pole head, the main-pole of 0.15 μm in thickness has been made of a Co-Zr-Nb amorphous film. The 50 % down density D50of 135 kFRPI could be reached by combining this head with the double-layered medium having a thinner Co-Cr layer of 0.25 μm.