Faculty of Physics - University of Bucharest

UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

Guest
2024-11-21 20:33

HOME CONFERENCES SEARCH LOGIN NEW USER IMAGES

Conference: Bucharest University Faculty of Physics 2008 Meeting

Section: Optics, Spectroscopy, Plasma and Lasers

Title:

Raman spectroscopy studies of C -(Ag, Sn, Al, Cu) films

Authors:

I.D. Feraru(1), C. Mic(1), C. Lungu(2), C. Porosnicu(2), A. Lungu(2), I. Jepu(2), O. G. Pompilian(2), D. Savastru(1), I.C. Vasiliu(1), M. Elisa(1), I. Gruia(3), C. E. A. Grigorescu(1)

Affiliation:

(1)National Institute R&D Optoelectronics INOE 2000, PO Box MG-5, Magurele, 77125 Romania

(2)National Institute R&D Laser, Plasma&Radiation PhysicsMagurele, 77125 Romania

(3)Faculty of Physics-University of Bucharest, Magurele, Romania

E-mail

feraru_i@yahoo.com

Keywords:

Raman spectroscopy,thermionic vacuum arc method, D and G carbon bands

Abstract:

Carbon-based coatings are known for their enhanced hardness and low friction coefficients, thus finding applications in cutting tools, metallic molds and antifriction layers on sliding surfaces of bearings built in various machines. This work presents Raman spectroscopy corroborated with optical microscopy studies of C-(Ag, Sn, Al, Cu) films deposited by the thermionic vacuum arc(TVA)method[1]. The TVA method uses two separate electron beams emitted by two externally heated tungsten cathodes. The electron beams evaporate the graphite and the metal used as anodes. C-(Ag, Sn, Al, Cu) films with thicknesses of a few microns were thus deposited on stainless steel substrates through simultaneous evaporation of C and the corresponding metal. To identify the contribution of amorphous versus diamond-like carbon bonds in the films we have performed Raman scattering measurements by means of a LABRAM-HR Horiba Jobin Yvon 800 UV-VIS-NIR spectrometer at INOE-2000, Magurele, Romania. The spectra were taken using a HeNe laser (632nm) on zones of the samples previously observed through optical microscopy. The contrast of different zones of an image was then accounted when the intensities of the carbon bands occurring in the spectra were calculated, thus making possible a relative estimation of the C-content of the films. Raman spectra indicate two broad bands: first broad band is situated between 1330 -1360 cm -1 (D band, i.e. disorder ) end the second is ranged between 1550-1580 cm-1 (G band, i.e.graphite-like). The ratios of the integral intensities (D/G ) of the two bands in the spectra belonging to different samples were calculated after peaks fitting. We remarked better resolved D and G bands in the C – (Cu, Ag) films. C-Sn films show an inhomogeneous composition (C-rich and respectively C-poor zones). [1]. C. P. Lungu, I. Mustata, G. Musa, A. M. Lungu, O. Brinza, C. Moldovan, C. Rotaru, R. Iosub, F. Sava, M. Popescu, R. Vladoiu, V. Ciupina, G. Prodan, N. Apetroaei, “Unstressed carbon-metal films deposited by thermionic vacuum arc method” J. Optoelectron. Adv. Mater. 8, 2006, pp. 74—77.