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Applied Optics

Applied Optics

APPLICATIONS-CENTERED RESEARCH IN OPTICS

  • Vol. 37, Iss. 28 — Oct. 1, 1998
  • pp: 6654–6663

Optical Properties of Alumina Titanium Carbide Sliders Used in Rigid Disk Drives

Peter de Groot  »View Author Affiliations


Applied Optics, Vol. 37, Issue 28, pp. 6654-6663 (1998)
http://dx.doi.org/10.1364/AO.37.006654


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Abstract

A common material for read–write sliders is a composite of alumina (Al2O3) and titanium carbide (TiC), with a grain size of the order of 1 μm. I derive the effective complex reflectivity of this material, using scalar diffraction theory and the known indices of refraction of Al2O3 and TiC. The effective reflectivity is a function of the relative surface area of the exposed TiC grains as well as of the numerical aperture of the collection optics. The theory resolves several known discrepancies between ellipsometry and reflectometry of Al2O3–TiC. The theory also predicts a systematic error in the phase shift on reflection calculation. These results are of considerable interest for surface shape metrology of the slider as well as for optical flying-height testing and control of pole-tip recession.

© 1998 Optical Society of America

OCIS Codes
(120.2130) Instrumentation, measurement, and metrology : Ellipsometry and polarimetry
(120.2830) Instrumentation, measurement, and metrology : Height measurements
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.4530) Instrumentation, measurement, and metrology : Optical constants
(120.4640) Instrumentation, measurement, and metrology : Optical instruments
(120.5410) Instrumentation, measurement, and metrology : Polarimetry

Citation
Peter de Groot, "Optical Properties of Alumina Titanium Carbide Sliders Used in Rigid Disk Drives," Appl. Opt. 37, 6654-6663 (1998)
http://www.opticsinfobase.org/ao/abstract.cfm?URI=ao-37-28-6654


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References

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  19. An alternative approach is to correlate the reflectance of the slider to the index of refraction by using an empirically derived equation. See K. H. Womack and A. Butler, “Determining the complex refractive index phase offset in interferometric flying height testing,” U.S. patent 5,781,299 (14 July 1998).

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