Graphitic carbon nanospheres: A Raman spectroscopic investigation of thermal conductivity and morphological evolution by pulsed laser irradiation

Journal Article · Mon Dec 07 00:00:00 EST 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4936596· OSTI ID:22492998

Agarwal, Radhe; Sahoo, Satyaprakash; Chitturi, Venkateswara Rao

Graphitic carbon nanospheres (GCNSs) were prepared by a unique acidic treatment of multi-walled nanotubes. Spherical morphology with a narrow size distribution was confirmed by transmission electron microscopy studies. The room temperature Raman spectra showed a clear signature of D- and G-peaks at around 1350 and 1591 cm{sup −1}, respectively. Temperature dependent Raman scattering measurements were performed to understand the phonon dynamics and first order temperature coefficients related to the D- and G-peaks. The temperature dependent Raman spectra in a range of 83–473 K were analysed, where the D-peak was observed to show a red-shift with increasing temperature. The relative intensity ratio of D- to G-peaks also showed a significant rise with increasing temperature. Such a temperature dependent behaviour can be attributed to lengthening of the C-C bond due to thermal expansion in material. The estimated value of the thermal conductivity of GCNSs ∼0.97 W m{sup −1} K{sup −1} was calculated using Raman spectroscopy. In addition, the effect of pulsed laser treatment on the GCNSs was demonstrated by analyzing the Raman spectra of post irradiated samples.

• OSTI ID: 22492998
• Journal Information: Journal of Applied Physics, Vol. 118, Issue 21; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CARBON NANOTUBES
GRAPHITE
LASER RADIATION
MORPHOLOGY
PEAKS
PULSES
RAMAN EFFECT
RAMAN SPECTRA
RAMAN SPECTROSCOPY
RED SHIFT
SPHERICAL CONFIGURATION
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
THERMAL CONDUCTIVITY
THERMAL EXPANSION
TRANSMISSION ELECTRON MICROSCOPY