Rajay Kumar

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Thermal transport in carbon nanotubes is explored using different laser powers to heat suspended single-walled carbon nanotubes ϳ5 ␮m in length. The temperature change along the length of a nanotube is determined from the temperature-induced shifts in the G band Raman frequency. The spatial temperature profile reveals the ratio of the contact thermal(More)
We exploit the strong plasmon resonance of gold nanoparticles in the catalytic decomposition of CO to grow various forms of carbonaceous materials. Irradiating gold nanoparticles in a CO environment at their plasmon resonant frequency generates high temperatures and strong electric fields required to break the CO bond. By varying the laser power, exposure(More)
We measure resonant Raman scattering of individual carbon nanotube bundles under axial strains of up to 17%. The main effect of this strain is to cause debundling of the nanotubes. The G band Raman spectra of metallic and semiconducting nanotubes respond differently to strain and debundling, giving insight into the nature of the broad metallic G − band line(More)
A review is given of Raman spectroscopy of carbon nanotubes under axial strain. Carbon nanotubes possess a high Young's modulus (1 TPa) and breaking strains of 5-15%. Resonance Raman spectroscopy reveals changes in the electronic energies and lattice structure of nanotubes under applied strain. Studies performed on composite materials, where nanotubes have(More)
We study the radial breathing mode ͑RBM͒ of resonant single walled carbon nanotubes within individual bundles. As strain is applied, significant debundling of the nanotubes occurs, causing an upshift in the RBM frequency. The RBM frequency is found to change irreversibly with strain, correlating more strongly with the total number of strains and relaxations(More)
A B S T R A C T We demonstrate selective burnout of individual carbon nanotubes that are electronically resonant with the incident laser energy. Raman spectroscopy and atomic force microscopy are used to quantify the burnout of nanotubes. The threshold laser power for rapid burnout is found to occur between 0.4 and 0.9 W/lm 2. At lower laser powers of 80(More)
We demonstrate a method for inducing strain in carbon nanotubes using standard lithographic techniques. In this work, aligned nanotubes are partially suspended over trenches made by chemical etching. Strain-induced downshifts as high as 31 cm −1 are observed in the Raman spectra, roughly corresponding to 1.1% strain. We also observe significant shifts in(More)
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Silt composed predominately of quartz occurs abundantly in the sedimentary material found in deposits worldwide. Its origin is still the subject of many debates, but one acknowledged source is due to glacial grinding. To examine this problem and test the apparent contradictory evidence in the literature, a series of experiments were performed. In these(More)
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