Raman scattering study of evaporated carbon nanostructured films

Abstract

The presence of carbon nanostructures in evaporated carbon thin films has been evidenced by Raman spectroscopy measurements. The films were grown by means of a conventional electron beam evaporation equipment, used to sublimate a graphite target and by varying the substrate temperature T s from room temperature (RT) up to 830°C. The effect of predeposited very thin cobalt films was also investigated. The Raman spectra of the carbon thin films are characterized by two bands near 1550 and 1400 cm −1 due to E 2g stretching mode of graphite (G band) and to the double resonance Raman scattering, responsible for the observation of the defect induced-D mode in graphite (D band). In particular, at 830°C the characteristic features of a nanometric carbon structure are evident: the A 1g radial breathing mode (RBM) at 150-300 cm −1 and the first overtone of the D peak at 2450-2650 cm −1 . The formation, at a specific temperature, of Co particles of size below 100 nm has been identified as the main factor in determining the carbon nanostructures' growth.

A DEEPSPITZERSURVEY OF CIRCUMSTELLAR DISKS IN THE YOUNG DOUBLE CLUSTER, h AND χ PERSEI

“…From our line of sight, h and χ Persei an extremely populous cluster projected out of the galactic plane by ∼ 200pc, and the Spitzer data reaches completeness limits of ∼ 51 µJy at [8], making extragalactic contamination of at least one cluster member very likely. To assess the probable frequency of contamination as a function of wavelength and magnitude, we use the IRAC number counts derived for the Bootes field from Fazio et al (2004) and the MIPS-24 µm counts derived from Papovich et al (2004). In Fazio et al (2004), the number counts are differential, estimating the number of galaxies per magnitude in half-magnitude bins 16 .…”

“…To assess the probable frequency of contamination as a function of wavelength and magnitude, we use the IRAC number counts derived for the Bootes field from Fazio et al (2004) and the MIPS-24 µm counts derived from Papovich et al (2004). In Fazio et al (2004), the number counts are differential, estimating the number of galaxies per magnitude in half-magnitude bins 16 .…”

“…DATA 2.1. IRAC 3.6-8 µm Data The Infrared Array Camera (IRAC; Fazio et al 2004) observed h and χ Persei on October 30, 2008 (AOR IDs 2182740, 21828608, 21828096, 21828864, 21828352, and 2182912). Solar activity was normal to below-average.…”

Large-scale fabrication of reduced graphene oxide-sulfur composite films for flexible lithium-sulfur batteries

“…2 d). Both GO and RGO-based films exhibit a D band at 1332 cm −1 and a G band at about 1600 cm −1 , which are normally stand for local defects/disorders and ordered sp 2 graphic carbon, respectively [36,57] . The intensity ratio of I D / I G was an indicator of the degree of disorder and average size of the sp 2 domains [36] .…”

Recent advances in linear and non‐linear Raman spectroscopy. Part III

“…The presence of carbon nanostructures in evaporated carbon thin films has been evidenced by Fazio et al [207] Diamond films grown by hot filament chemical vapour deposition on WCCo were investigated by Donato et al [208] The changes in the Raman spectrum induced by the different pretreatments of the substrate and/or different growth parameters of the films were discussed. The cross-linking content and the polymerisation degree of poly(methylmethacrylate) PMMA thin films have been investigated by Fazio et al [209] by infrared and micro-Raman spectroscopic techniques.…”