The Magnetic properties and recording characteristics of magnetic recording media with magnetic layer devided by Cr interlayer (multilayered media)have been investigated. The reduction in the media noise and the improvement in SNR are observed. At the interlayer thickness of 3nm, SNR is higher than that of CoCrTa singlelayered media. If the interlayer thickness is thicker than 3nm, O/W is lower compared with singlelayered media. When the thickness of two magnetic layers are equal, the multilayered media appear the good recording characteristics.

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A Co-Cr film was continuously deposited on a very thin Co-Cr initial layer deposited at high incident angle. The film had tilted magnetic anisotropy like films deposited at high incident angle. A Co-Cr film deposited directly on a polymer substrate at low incident angle had a c-axis around the film normal. On the other hand, the Co-Cr film deposited at the low incident angle on the initial layer had a tilted c-axis from the film normal. it was considered that the tilted c-axis grew epitaxially on the initial layer.

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While the thickness of main-pole must be thin to improve the high linear density response in perpendicular magnetic recording with a single-pole type head, the magnetic interaction between the main-pole and the backlayer of the double-layered media is weakened. In this study, the experimental results show that the double-layered medium with the thin Co-Cr recording layer tightens the magnetic interaction, therefore, the linear density response is improved. In addition, the ferrite-substrate disks are investigated for the high frequency applications, which will achieve high linear density and high data rate recording.

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Microstructure differences for CoPt thin films sputtered between high and low Ar pressure were found. The films deposited under high Ar Pressure showed amorphous phase with oxigen atoms. Low Ar pressure produced Pt content, modulations in crystal grains but amorphous phase. Magnetic properties of low Ar pressure films dependended on perpendicular magnetic anisotropy and on on crystal grainsize. Another origin was thought to affect the magnetic properties of high Ar pressure films. DC erased media noise decreased as the grain size decreased for both media. Trandsition-related media noise also redused as the grain shrinked for high Ar pressure films but not for low Ar pressure films.

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In yoke type MR heads. Barkhausen noise occurs differently depending on various applied fields. The place causing the noise is able to be specified by comparing the observed change of noise with the calculated field distribution in the head when an internal bias is superimposed to a uniform external field. Using a recording coil current instead of a uniform external field. the noise from a bottom yoke or a substrate is clearly detected.

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A thinner main-pole film is required for high linear density reproduction in Perpendicular magnetic recording. The Co-Zr-Nb amorphous films have the sufficiently low coercivity over 0.08μm in thickness in our experiment, but their domain wall structure nevertheless turn to the cross-tie walls from the bloch walls less than 0.1μm. We found that the main-poles with the cross-tie wall showed much lower reproduction-sensitivity than those with the bloch wall. The thinnest main-pole within the range of the bloch wall structure was 0.12μm. It brought the high D_<50> Of 170kFRPI, and showed no deterioration of the sensitivity.

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