Different substrate materials effect on structure of ta-C films by Raman spectroscopy for magnetic recording sliders

Raman spectra, using visible (514 nm) and ultraviolet (244 nm) excitation, of tetrahedral amorphous carbon (ta-C) films of thickness of 5 nm have been studied as a function of different substrates materials. These materials are Fe-Co (Fe: 67 at.%, Co: 33 at.%) alloy, Fe-Ni alloy (Fe: 18 at.%, Ni: 82 at.%), An and Al2O3 TiC (Al2O3: 64 at.%, TiC: 36 at.%), which are mainly used in magnetic recording sliders. The spectra show that the films deposited on Al2O3-TiC contain the highest sp(3) content, with a lower sp(3) content observed in films deposited to Fe-Co and Fe-Ni alloys. The lowest sp(3) content was observed in films on the An substrate. The results also indicate that the anti-wear performance of ta-C film on different substrates varies as Al2O3-TiC (the best) > Fe-Co and Fe-Ni alloy > Au (the worst). Also mechanisms are proposed to explain the effect of substrate material on these thin film properties. (C) 2007 Elsevier B.V. All rights reserved.