Xiaozhong Dang

Advanced probe head for perpendicular recording

Basic design and recording performance of the advanced probe heads are described. Excellent writability of the advanced probe heads is demonstrated by a series of overwrite (OW) and nonlinear transition shift (NLTS) saturation measurements. Write currents as low as 5 mA/sub o-p/ are required for recording. Excellent OW can be obtained with both high and low OW ratios. Media with vibrating sample magnetometry coercivities as high as 7000 Oe can be recorded with OW of 30 dB. Better than -14 dB of NLTS was measured at a linear density of 600 kfci. Minimal side-writing has been observed using the advanced probe heads with square pole shape. External field sensitivity of the advanced probe heads has also been shown to be excellent as larger than 58 Oe of external field is required to erase a low density signal on a 3380-Oe disk. Modeling results also show that the basic architecture of advanced probe head is extendible to 0.1 /spl mu/m square pole.

High linear density study of advanced single pole head

In this work, we present the general head design and magnetic recording performance of our second-generation advanced probe heads. These heads require as low as 5-mAo-p write currents for optimal recording. We demonstrate superior writeability via a series of overwrite (OW) and nonlinear transition shift (NLTS) saturation measurements. Excellent OW can be obtained with both high and low OW ratios. Media with VSM coercivities as high as 5500 Oe can be recorded with OW of 32 dB. We measured better than -12 dB of NLTS at a linear density of 1500 kfci. In this work, we present data where the magnetic read width (MRW) for the same read head is smaller when measured on perpendicular media compared to longitudinal media. We also show that the external field sensitivity of the advanced probe heads is excellent as larger than 32 and 23 Oe of external fields are required to erase a low-density signal on 3380- and 2200-Oe disks, respectively. Overall, the basic architecture of this advanced probe head is extendable to 0.12-/spl mu/m write track-width, while we discover no remanence in the pole.

Inductive write heads using high moment pole materials for ultrahigh areal density demonstrations

In this paper, the high moment materials and their applications in the write heads for these areal density demonstrations will be discussed. Due to high intrinsic magnetic anisotropy and magnetostriction, which is typically about 4.5x10/sup 5/, FeCoN films exhibit typical coercivity in excess of 50 Oe, and isotropic in-plane magnetic properties, under un-optimised process conditions. A typical hysteresis loop of the film is shown.

Flat-top pole write head design

A write head design with pedestal-defined throat and flat-top pole is presented. The flat-top pole design enables critical dimension control and extendibility to narrower feature size. Write head performance improves further by implementing a single-layer six-turn, closely packed coil with yoke length of 14 /spl mu/m and incorporating a sputtered high moment material on both top and bottom poles. With write current of 40 mA, better than 35 dB overwrite and less than 16% (-16dB) nonlinear transition shift can be achieved on the medium with coercivity of 4400 Oe and Mrt of 0.32 memu/cm/sup 2/ at areal densities up to 60 Gb/in/sup 2/.

High performance writer using high moment sputtered films in top and bottom poles

Sputter-deposited high-moment materials were used in top and bottom poles of a writer that has a pedestal defined zero throat. The high moment materials used were FeRhN/CoZrCr laminated films with a B/sub s/ of 20.3 kG. In the top pole, the sputtered materials were used as the flux enhancement layer with a thickness of 0.5 /spl mu/m. In the bottom pole, the sputtered film forms a pedestal, which has a vertical sidewall at the top to define the zero throat, as well as a tapered foot at the bottom to allow a better flux passage. As a result, the overwrite can be improved by about 9 dB, as compared to heads that employ only conventional Ni/sub 45/Fe/sub 55/ electroplated material in top and bottom poles.

Flat top pole writer design

In this paper, the design and magnetic performance of a new writer design with flat top pole are discussed. In this study, flat top pole heads with throat height of 2.0 /spl mu/m and magnetic track width of 0.28/spl mu/m were made with conventional plating/milling process. Finite element modeling (FEM) was also used to calculate head field and field gradient at the media. Modeling data show that good writing performance can be achieved by optimising the head design and implementing high moment material.