Theoretical Investigation of X-Ray Absorption near Edge Spectroscopy (XANES) Angular Dependence of Aligned Carbon Nanotubes Grown by DC HF CVD Process

Bridinette Thiodjio Sendja^1*, Rolant Eba Medjo², Jeannot Mane Mane¹, Germain Hubert Ben-Bolie³, Pierre Owono Ateba³

¹Ecole Nationale Supérieure Polytechnique (National Advanced School of Engineering), Department of Mathematics and Physical Sciences, University of Yaoundé I, Yaounde, Cameroon.
²Physics Department, Faculty of Science, University of Douala, Douala, Cameroon.
³Physics Department, Faculty of Science, University of Yaoundé I, Yaounde, Cameroon.

DOI: 10.4236/msa.2015.65043                

Abstract

Carbon nanotubes (CNTs) grown on plain substrates SiO2/Si(100) by a direct current and hot filaments catalytic chemical vapor deposition process have been studied by synchrotron X-ray absorption near edge spectroscopy (XANES) technique to theoretically investigate the angular-dependence of carbone (C) K-edge π* and σ* transitions. Experimental XANES spectra show that π* resonance increases with the incidence angle from normal to grazing incidence angle while σ* resonance decreases. This has been explained by the sine-square and cosine-square dependencies of π* and σ* intensities, respectively. These results were confirmed by theoretical XANES curves of highly oriented pyrolytic graphite (HOPG) and CNTs plotted versus incidence angle. It has been shown that π* and σ* transitions strongly depend on the nature of polarized light (linearly or circularly). At the linear polarized light, π* resonance is a preference as well as at right-circular polarized. At the left-circular polarized light, σ* resonance is a preference. The π* intensities are high at parallel orientation and the σ* intensities are low at normal orientation. The smallest π* intensity is noticed at normal orientation, where the π* orbitals are supposed to be lying parallel to the surface plane for perfectly aligned HOPG or CNTs. This explains the incomplete extinction of π* intensity. We noticed at parallel orientation a region where any π* and σ* transitions did not expect because of the lack of polarization light.

Keywords

Angular Dependence, XANES, Normal Incidence, Grazing Incidence, Carbon Nanotubes, Intensity

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Iijima, S. (1991) Helical Microtubules of Graphitic Carbon. Nature, 56, 354. http://dx.doi.org/10.1038/354056a0
[2]	Melechko, A.V., Merkulov, V.I., McKnight, T.E., Guillon, M.A., Klein, K.L., Lowndes, D.H. and Simpson, M.L. (2005) Vertically Aligned Carbon Nanofibers and Related Structures: Controlled Synthesis and Directed Assembly. Journal of Applied Physics, 97, Article ID: 041301. http://dx.doi.org/10.1063/1.1857591
[3]	Ren, Z.F., Huang, Z.P., Xu, J.W., Wang, J.H., Bush, P., Siegal, M.P. and Provencio, P.N. (1998) Synthesis of Large Arrays of Well-Aligned Carbon Nanotubes on Glass. Science, 282, 1105. http://dx.doi.org/10.1126/science.282.5391.1105
[4]	Chhowalla, M., Teo, K.B.K., Ducati, C., Rupesinghe, N.L., Amaratunga, G.A.J., Ferrari, A.C., Roy, D., Robertson, J. and Milne, W.I. (2001) Growth Process Conditions of Vertically Aligned Carbon Nanotubes Using Plasma Enhanced Chemical Vapor Deposition. Journal of Applied Physics, 90, 5308. http://dx.doi.org/10.1063/1.1410322
[5]	Cojocaru, C.S., Senger, A. and Le Normand, F. (2006) A Nucleation and Growth Model of Vertically-Oriented Carbon Nanofibers or Nanotubes by Plasma-Enhanced Catalytic Chemical Vapor Deposition. Journal of Nanoscience and Nanotechnology, 6, 1331. http://dx.doi.org/10.1166/jnn.2006.144
[6]	Mane, J., Cojocaru, C.S., Barbier, A., Deville, J.P., Thiodjio Sendja, B. and Le Normand, F. (2007) GISAXS Study of the Alignment of Oriented Carbon Nanotubes Grown on Plain SiO2/Si(100) Substrates by a Catalytically Enhanced CVD Process. Physica Status Solidi (a), 1, 21.
[7]	Thiodjio Sendja, B., Eba Medjo, B., Mane Mane, J., Ben Bolie, G., Diop, D. and Owono, A. (2010) A GISAXS Study of the Angular Dependence of Carbon Nanotubes Grown on a Plain Substrate by the DC HF CCVD Process. Physica Scripta, 82, Article ID: 025601. http://dx.doi.org/10.1088/0031-8949/82/02/025601
[8]	Rosenberg, R.A., Love, P.J. and Rehn, V. (1986) Polarisation-Dependant Near-Edge X-Ray-Absorption Fine Structure of Graphite. Physical Review B, 33, 4034. http://dx.doi.org/10.1103/PhysRevB.33.4034
[9]	Fischer, D.A., Wentzcovitch, R.M., Carr, P.G., Continenza, A. and Freeman, A.J. (1991) Graphitic Interlayer States-A Carbon-K Nearedge X-Ray-Absorption Fine-Structure Study. Physical Review B, 44, 1427. http://dx.doi.org/10.1103/PhysRevB.44.1427
[10]	Eba Medjo, R., Thiodjio Sendja, B., Mane Mane, J. and Owono Ateba, P. (2009) XAS Study of the Orientation of Oriented Carbon Nanotube Films. Physica Scripta, 80, Article ID: 055602. http://dx.doi.org/10.1088/0031-8949/80/05/055602
[11]	Chiou, J.W., Yueh, C.L., Jan, J.C., Tsai, H.M., Pong, W.F., Hong, I.-H., Klauser, R., Tsai, M.-H. and Chang, Y.K. (2002) Electronic Structure of the Carbon Nanotube Tips Studied by X-Ray-Absorption Spectroscopy and Scanning Photoelectron Microscopy. Applied Physics Letters, 81, 4189. http://dx.doi.org/10.1063/1.1523152
[12]	Tang, Y.H., Sham, T.K., Hu, Y.F., Lee, C.S. and Lee, S.T. (2002) Near-Edge X-Ray Absorption Fine Structure Study of Helicity and Defects in Carbon Nanotubes. Chemical Physics Letters, 366, 636. http://dx.doi.org/10.1016/S0009-2614(02)01620-2
[13]	Schiessling, J., Kjeldgaard, L., Rohmund, F., Falk, L.K.L., Campbell, E.E.B., Nordgren, J. and Bruhwiler, P.A. (2003) Synchrotron Radiation Study of the Electronic Structure of Multiwalled Carbon Nanotubes. Journal of Physics: Condensed Matter, 15, 6563. http://dx.doi.org/10.1088/0953-8984/15/38/022
[14]	Li, Z.R., Zhang, L., Resasco, D.E., Mun, B.S. and Requejo, F.G. (2007) Angle-Resolved X-Ray Absorption near Edge Structure Study of Vertically Aligned Single-Walled Carbon Nanotubes. Applied Physics Letters, 90, Article ID: 103115. http://dx.doi.org/10.1063/1.2709506
[15]	Mane, J.M., Le Normand, F., Medjo, R.E., Cojocaru, C.S., Ersen, O., Senger, A., Laffon, C., Sendja, B.T., Biouele, C.M., Ben-Bolie, G.H., Ateba, P.O. and Parent, P. (2014) Alignment of Vertically Grown Carbon Nanostructures Studied by X-Ray Absorption Spectroscopy. Materials Sciences and Applications, 5, 966-983. http://dx.doi.org/10.4236/msa.2014.513098
[16]	Stohr (1992) Analysis of K-Shell Excitation Spectra by Curve Fitting. Journal of NEXAFS Spectroscopy, 25, 211-238. http://dx.doi.org/10.1007/978-3-662-02853-7_7
[17]	Hemraj-Benny, T., Banerjee, S., Sambasivan, S., Balasubramanian, M., Fischer, D.A., Eres, G., Puretzky, A.A., Geohegan, D.B., Lowndes, D.H., Han, W.Q., Misewich, J.A. and Wong, S.S. (2005) Near-Edge X-Ray Absorption Fine Structure Spectroscopy as a Tool for Investigating Nanomaterials. Small, 2, 26-35. http://dx.doi.org/10.1002/smll.200500256
[18]	Pate, B.B., Hecht, M.H., Binns, C., Lindau, I. and Spicer, W.E. (1982) Photoemission and Photon-Stimulated Ion Desorption Studies of Diamond(111): Hydrogen. Journal of Vacuum Science & Technology, 21, 364-367. http://dx.doi.org/10.1116/1.571781