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

Abstract

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.%), Au and Al 2O 3–TiC (Al 2O 3: 64 at.%, TiC: 36 at.%), which are mainly used in magnetic recording sliders. The spectra show that the films deposited on Al 2O 3–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 Au substrate. The results also indicate that the anti-wear performance of ta-C film on different substrates varies as Al 2O 3–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.