Visible Raman spectroscopy of carbon films synthesized by ion-plasma sputtering of graphite

  • PDF / 401,213 Bytes
  • 10 Pages / 584.957 x 782.986 pts Page_size
  • 61 Downloads / 239 Views

DOWNLOAD

REPORT


Gaziz A. Yermekov and Timur E. Nurmamytov National Nanotechnological Laboratory Open Type, Al-Farabi KazNU, Almaty 050012, Kazakhstan

Renata R. Nemkayevaa) National Nanotechnological Laboratory Open Type, Al-Farabi KazNU, Almaty 050012, Kazakhstan; and Laboratory of engineering profile, Al-Farabi KazNU, Almaty 050040, Kazakhstan

Nazim R. Guseinov National Nanotechnological Laboratory Open Type, Al-Farabi KazNU, Almaty 050012, Kazakhstan

Rustam K. Aliaskarov Laboratory of engineering profile, Al-Farabi KazNU, Almaty 050040, Kazakhstan (Received 2 July 2015; accepted 7 December 2015)

The article discusses the structure and properties of noncrystalline carbon films synthesized by ion-plasma sputtering of a graphite target in an argon atmosphere at direct current. Analysis of the molecular structure of carbon films was performed using Raman spectroscopy and dependence of the structure of synthesized films on the synthesis temperature and substrate material was revealed. Besides the main G peak possesses the values in a broad frequency range from 1500 to 1575 cm1. The evolution of molecular structure peculiarities of synthesized carbon films depending on the synthesis conditions was clearly shown using the numerical methods of the Raman spectra decomposition. Studies of the optical spectra showed that the band gap of synthesized films varies from 0.78 to 1.67 eV and with increasing optical band gap, the value of G peak position decreases under laser excitation of 2.62 and 1.96 eV. I. INTRODUCTION

The great interest of scientists toward carbon is caused, first of all, by the existence of diversity of its various structural forms, attractive electronic and physical properties. Besides the known carbon crystal structures of graphite, diamond and lonsdaleite, over the last 30 years, the new forms of existence of carbon structures such as nanotubes, fullerenes, graphene and graphane were discovered.1–4 The electrical, optical and physical properties of atomic carbon structures depend not only on sp1, sp2 and sp3 hybridization of carbon bonds, but also on the forms of organization of carbon atoms.5,6 The essential difference only by the one parameter, such as conductivity, enables wide application of the obtained new carbon structures in the creation of various devices and new composite materials.7,8 The interest of no small importance is attracted by such structures as amorphous carbon (a-C), tetragonal amorphous carbon (ta-C) and others.9–15 Production of various

Contributing Editor: Mauricio Terrones a) Address all correspondence to these authors. e-mail: [email protected], [email protected] DOI: 10.1557/jmr.2015.391 J. Mater. Res., Vol. 31, No. 1, Jan 14, 2016

forms and molecular structures of carbon depends on the conditions and methods of their synthesis. Structural modification of carbon films is defined by different ratios of sp1, sp2 and sp3 hybridized bonding. Increase of the local concentration of sp3 or sp2 hybridized bonds per unit of volume can lead to the formation of nanoclusters in the form of graphite, tetrago

Data Loading...