ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
CoCr thin films were prepared by dc magnetron sputtering, on aluminum substrates in a dual-sided sputtering system. Ouchi and Iwasaki [J. Appl. Phys. 57, 4013 (1985)] have reported that for magnetron sputtered CoCr thin films on a substrate at constant temperature, the coercivity is dependent on the substrate temperature and not on the deposition rate. However, for applications in which no heat sinking is applied during deposition the temperature of the film and the substrate increases with time which produces a film with a coercivity gradient that affects both the magnetic and the recording properties. This report investigates the effects of this coercivity gradient on the recorded output amplitudes. The average perpendicular coercivity Hc(⊥) was observed to increase from 65 to 440 Oe, and then decrease with further increase in thickness. The average dispersion of the c axis, Δθ50, decreased from 6.5°, for the thin films, to 2.8° for the thick films. Coercivity measurements reveal a relatively soft film [Hc(⊥)〈100 Oe] for the initial layers. The initial soft layer acts as a magnetic flux sink as does the underlayer in a double-layer media when recorded using a thin-film head. The films with thicker soft layers (100-A(ring)/s deposition rate) show 30–40 % more output when compared to films with thin soft initial layers (lower deposition rates). Comparable recorded outputs were observed when the thick soft layer (1 μm thick at 100-A(ring)/s deposition rate) was replaced with an Fe-Ni-Cr ferromagnetic alloy [Hc(⊥)〈80 Oe].
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.337822
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