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HH11.2.1

Resonance Raman Spectroscopy to Study and Characterize Defects on Carbon Nanotubes and other Nano-Graphite Systems Ado Jorio,1 Luiz Gustavo Cançado,1 Bernardo R. A. Neves,1 Mauricio de Souza,1 Cristiano Fantini,1 Marcos A. Pimenta,1 G. Medeiros-Ribeiro,3 Georgii G. Samsonidze,2 Shin Grace Chou,4 Gene Dresselhaus,5 Mildred S. Dresselhaus,2, 6 A. M. Rao,7 Alexander Grüneis,8 and Riichiro Saito8 1

Depto. de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. Dept. of Electrical Engineering and Computer Science, MIT, Cambridge, MA, USA. 3 Laboratório Nacional de Luz Síncrotron, Campinas, São Paulo, Brazil. 4 Dept. of Chemistry, MIT, Cambridge, MA, USA. 5 Francis Bitter Magnet Laboratory, MIT, Cambridge, MA, USA. 6 Dept. of Physics, MIT, Cambridge, MA, USA. 7 Dept. of Physics and Astronomy, Clemson University, South Carolina 29634, USA 8 Dept. of Physics, Tohoku University and CREST JST, Sendai, Japan. 2

ABSTRACT The use of resonance Raman spectroscopy (RRS) to study and characterize single wall carbon nanotubes (SWNTs) is discussed, focusing on preliminary efforts for the development of the RRS to characterize defects in SWNTs. The disorder-induced D-band, disorder-induced peaks just above the first-order allowed graphite G-band, as well as the intermediate frequency modes (IFMs) appearing between the RBM and the D/G spectral region are addressed. RRS on nanographite ribbons and on a step-like defect in highly ordered pyrolytic graphite (HOPG) sheds light into the problem of characterizing specific defects in nano-related carbons.

INTRODUCTION Major effort has been made to develop the nanotechnology based on single wall carbon nanotubes (SWNTs) [1]. Some of the big challenges for the development of SWNT nanodevices are the selective (n,m) growth, SWNT manipulation, tube-metal contacts, tube-tube junctions, tube functionalization. While microscopic techniques are largely used for characterization of specific structures for a given (n,m) nanotube, the development of spectroscopic techniques has been shown to be very effective for simple, quick, cheap and non-destructive characterization of SWNT properties. Photoluminescence (PL) [2] and resonance Raman spectroscopy (RRS) [3] have been developed at the single SWNT level and are now largely used to characterize the population of (n,m) SWNTs in a sample. RRS has the advantage of studying both electrons and phonons, and gives information about the presence of defects and impurities in the samples [4]. While RRS is well established to determine the properties of a perfect SWNT, the ability of this technique to characterize defects is still poorly developed [3,4]. The big challenge for researchers working with RRS on SWNTs is the development of the RRS technique for the characterization of specific defects in a given (n,m) tube. By defects we mean any structure that modifies the perfect atomic structure of a nanotube, but useful for device production. In this

HH11.2.2

paper we describe our preliminary efforts to make RRS a tool ab