Vladyslav A. Vas'ko

Magnetic recording demonstration over 100 Gbit/In/sup 2/

Areal density growth has enabled hard disk drives to continually fulfill the demands from new enterprise, desktop, and consumer applications. The demonstration of 100 Gb/in/sup 2/ is another milestone that was achieved recently and is described in this paper. The recording demonstration employed fully integrated magnetic recording heads and thermally stable multilayer antiferromagnetically coupled (AFC) media through a commercially available channel chip. At a track density of 149 ktpi and linear density of 680 kbpi, the achieved off-track capability with 5% track squeeze was 10% of the track pitch, while maintaining a raw bit-error rate (BER) of 10/sup -4/ or better. This yielded an areal density of 101 Gb/in/sup 2/ with measured on-track raw BER of 5/spl times/10/sup -5/.

Structure, stress, and magnetic properties of high saturation magnetization films of FeCo

Thin (/spl sim/2000 /spl Aring/) films of Fe/sub 60/Co/sub 40/ have been prepared by sputtering on Si/SiO/sub 2/, Si/AlO/sub x/, AlTiC/AlO/sub x/, AlTiC/AlO/sub x//NiFe, and AlTiC/AlO/sub x//NiFeCr substrates using an alloy Fe/sub 60/Co/sub 40/ target. The structure of the films was characterized by means of X-ray diffraction and transmission electron microscopy (TEM). Surface roughness was characterized by atomic force microscopy (AFM). Stress, transport, and magnetic measurements were conducted. We observed correlation in the following pairs of properties: coercivity-stress, grain size-stress, and coercivity-grain size. Although individual films had a stress in the wide range of compressive 2.5/spl times/10/sup 10/ Dyne/cm/sup 2/ to tensile 1.3/spl times/10/sup 10/ Dyne/cm/sup 2/, which depended to some degree on the material of the substrate and underlayer, we found that biaxial stress and coercivity seem to be described by a general trend, with coercivity being as low as 19 Oe at intermediate tensile stress and as high as 225 Oe at high compressive stress. The unstrained lattice parameter and Youngs modulus of the alloy Fe/sub 60/Co/sub 40/ were also determined.

High Magnetic Saturation Poles for Advanced Perpendicular Writers

Advanced perpendicular writers continue to demand maximum write fields, fast rise times at ever vanishing head-media spacing and strict reliability standards. This means that the asymptotic progression to a 2.4 T pole with nearly ideal magnetic response continues. At the same time we must control critical pole dimensions, fabricate at a reasonable cost while protecting against corrosion and erasure risks. We will review progress made to meet this challenge in a discussion of high moment materials utilizing electroplating and sputter deposition for single layer films and laminates. Concerns for corrosion will be assessed and minimized by controls on key contaminants. Micromagnetic modeling will be used to study the phenomenology and expected performance impacts of these various materials and structures. Results will be used to provide a better insight into the potential materials/design tradeoffs that must be made. In conclusion, performance and reliability will be assessed through electrical testing.