Raman spectra diamond film

To evaluate the crystallinity of the films, Raman spectroscopy is used. A typical Raman spectrum is presented in Fig. 4. Of the crystalline diamond, a narrow peak at a frequency of 1332 cur1 is characteristic, which is caused by the first-order phonon scattering by the crystal lattice. The non-diamond carbon is represented in the spectrum by two diffuse bands at ca. 1350 and 1550 cm-1. When comparing the peaks height, one should keep in mind that the Raman signal is 50 times more sensitive to the non-diamond carbon than to the crystalline diamond [20], In the high-quality diamond films used as electrodes, the non-diamond carbon component rarely exceeds 1%. Raman spectroscopy data have been corroborated by the independent impedance spectroscopy measurements (see below). According to [21], the inner layer of a diamond film is enriched with the admixture of non-diamond carbon as compared to its outer layer. 

Fig. 6.2 Raman spectrum of boron-doped diamond film on silicon (a) silicon, (b) boron atoms, (c) diamond (sp3 carbon), and (d) other carbon forms (amorphous)...

Figure 16 shows the Raman spectrum of a DLC film deposited by the IBAD technique. The Raman spectra for diamond like materials provide information on the sp bonding. The characteristic features of Raman spectra of diamond like materials consist of a graphite-like (G) peak and a disorder (D) peak in the regions 1500-1550 cm and 1330-1380 cm respectively. The relative intensities of the G and D peaks can be used to indicate qualitatively the concentration of graphite crystallites of... 

FIGURE 5.4 SEM image and Raman spectrum of diamond film obtained by the combustion flame method t= 1.05. 

The carbon films obtained were diamond crystals (Figure 5.4(a)). The diamond crystals present predominantly a (111) facet. Raman spectrum of the film is shown in Figure 5.4(b). The sharp peaks due to diamond detected at 1335 cm showed the good quality of diamond. The average crystal size is about 10 pm. The influence of the ratio of acetylene to oxygen and of substrate temperature on the qualities and orientation of diamond have been discussed in a previous paper [33]. 

Figure 6.26 Raman spectrum of an ultrananocrystalline diamond film at different excitation wavelengths ( Elsevier 2000).

Figure 5.4 Raman spectra (Xf c= 1064 nm) of PPY/SWNT composites obtained by electropolymerization ofpyrrole on a SWNT film in HCI 0.5 M. Curve 1 corresponds to the SWNT film Raman spectrum. Curves 2-6 show the evolution of the Raman spectrum after 6, 2, 25, 50, and 100 cycles, respectively, carried out in the potential range (- -100 - -800) m V vs. SCE with a sweep rate of 100 mV s Curve 7 corresponds to the composites described by curve 6 after interaction with NH4OH 1 M solution. (Reprinted with permission from Diamond and Related Materials, Electrochemical and vibrational properties of single-walled carbon nanotubes in hydrochloric acid solutions by 5. Lefrant, M. Baibarac, I. Baltog et al., 14, 3-7, 873-880. Copyright (2005) Elsevier Ltd)...

Figure 3.6 Raman spectra of carbon coatings. Spectrum (a) is from a natural gem-quality diamond. Spectrum (/>) is from a high-quality diamond film. Spectrum (c) is from a diamond-like (amorphous) carbon coating. Spectrum (d) is from a glassy carbon film. ...

To date, the phonon confinement effects have not been explicitly detected for CVD diamond films and results remained unsatisfactory in the case of DND. To improve the agreement between the predictions of the model and experimental Raman spectra of DND, effects such as crystal size distribution, lattice defects, and the energy dispersion of the phonon modes were taken into consideration and incorporated into the PCM. This work has shown that phonon wave vectors from small vibration domains lead to a broad shoulder peak at 1250 cm", that is often observed in the Raman spectrum of DND. Although the agreement between experimentally obtained and calculated Raman spectra has been significantly improved, some limitations remain, as was pointed ont in Ref. 98. The limitations imposed by the small ND size on the applicability of the PCM arise from the assumption that nanocrystals of 3-20 nm in size, showing extensive surface reconstruction and lattice defects, are assumed to have the phonon density of states of bulk diamond. 

Figure 24 Typical Raman spectrum of -type doped carbon. Film laser wavelength = 632.8 nm dashed lines = spectral contributions solid line = fitting curve superimposed to the spectrum [59]. (Reproduced from Diamond and Related Materials, 8, Rzepka, E., et al.. Contribution of sp clusters in films and fibers obtained from camphor, pp, 481-484. Copyright 1999, with permission from...

Figure 33 Anti-Stokes Raman spectrum of DLC films observed under the 1236-A excitation [73]. (Reproduced from Journal of Non-Crystalline Solids, 227-230, Ivanov-Omskii, V. I., et al.. Bonded and non-bonded hydrogen in diamond-like carbon, pp. 627-630. Copyright 1998, with permission from Elsevier-Science.)...

Obtaining and interpreting Raman spectra of gemstones and related materials are popular experimental topics. Diamond is a favorite because it fascinates students and because the spectrum is easy to obtain. O Brien and co-workers used diamond as a device to introduce students to the more general topic of carbon Raman spectroscopy [6]. Once obtained, the diamond spectrum is compared to the spectrum of diamondlike carbon. Voor and co-workers looked at chemical-vapor-deposited diamond film using a homemade Raman microprobe [5]. 

Fig. 2.4. Topical Raman spectrum of a polycrystaUine CVD diamond film.

Semiconducting diamond films - low and high boron doping. Two essential sharp features appear in the Raman spectrum at... 

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