X-ray diffraction and raman spectroscopy characterization of isotropic pyrocarbon obtained by hot wall chemical vapor deposition

Abstract

Varying the flow rate of natural gas from 50 to 80 to 120 l/h, isotropic pyrocarbon produced by hot wall chemical vapor deposition at 1000 °C were examined by X-ray diffraction and Raman spectroscopy. The X-ray data were evaluated by Scherrer equation, and the intensity ratio of D to G band derived from Raman data was used to evaluate the lateral extension of isotropic pyrocarbon. The experimental results show that the d ₀₀₂-spacing of isotropic pyrocarbon decreases from 0.3499 nm to 0.3451 nm, while the stack height increases from 6.5 to 8.4 nm with the increase of flow rate of natural gas. The intensity ratio of D to G band and lateral extension of isotropic pyrocarbon increases with natural gas flow rate increasing. After heat treatment, all the crystallite parameters (stack height, lateral extension, and d ₀₀₂-spacing) decrease, indicating the improvement of the arrangement of the basic structural units of isotropic pyrocarbon.

Keywords

isotropic pyrocarbon / X-ray diffraction / raman spectroscopy / chemical vapor deposition / characterization

References

[1] Tuinstra F, Koenig JL Raman Spectrum of Graphite[J]. J. Chem. Phys., 1970, 53(3): 1 126-1 130.

[2] Cancado LG, Takai K, Enoki T, . Measuring the Degree of Stacking Order in Graphite by Raman Spectroscopy [J]. Carbon, 2008, 46(2): 272-275.

[3] Vidano RP, Fischbach DB, Willis LJ, . Observation of Raman Band Shifting with Excitation Wavelength for Carbons and Graphites[J]. Solid State Commun., 1981, 39(2): 341-344.

[4] Wang Y, Alsmeyer DC, McCreery GL Raman Spectroscopy of Carbon Materials: Structural Basis of Observed Spectra [J]. Chem. Mater., 1990, 2(5): 557-563.

[5] Nemanich RJ, Solin SA First- and Second-order Raman Scattering from Finite-size Crystals of Graphite [J]. Phys. Rev. B, 1979, 20(2): 392-400.

[6] Thomsen C, Reich S Double resonant Raman Scattering in Graphite [J]. Phys. Rev. Lett., 2000, 85(24): 5 214-5 217.

[7] Zickler GA, Smarsly B, Gierlinger N, . A Reconsideration of the Raltionship between the Crystallite Size La of Carbons Determined by X-ray Diffraction and Raman Spectroscopy[J]. Carbon, 2006, 44(15): 3 239-3 246.

[8] Zhang DS, Li KZ, Lu JH, . The Influence of Deposition Temperature on the Microstructure of Isotropic Pyrocarbon Obtained by Hot Wall Chemical Vapor Deposition[J]. J. Mater. Sci., 2011, 46(10): 3 632-3 638.

[9] Sadezhy A, Mukenhuber H, Grothe H, . Raman Microscopy of Soot and Related Carbonaceous Materials: Spectral Analysis and Structural Information [J]. Carbon, 2005, 43(8): 1 731-1 742.

[10] Cuesta A, Dhamelincourt P, Laureyns J, . Raman Microprobe Studies on Carbon Materials [J]. Carbon, 1994, 32(8): 1 523-1 532.

[11] Jamhari T, Roid A, Casado J Raman Spectroscopic Characterization of some Commercially Available Carbon Black Materials [J]. Carbon, 1995, 33(11): 1 561-1 565.

[12] Escribano R, Sloan JJ, Siddique N, . Raman Spectroscopy of Carbon-containing Particles[J]. Vib Spectrosc., 2001, 26(2): 179-186.

[13] Al-Jishi R, Dresselhaus G Lattice Dynamical Model for Graphite [J]. Phys. Rev. B, 1982, 26(8): 4 514-4 522.

[14] Lespade P, Marchand A, Couzi M, . Characterisation De Materiaux Carbones Par Microspectrometrie Raman[J]. Carbon, 1984, 22(4–5): 375-385.

[15] Li X, Tang ZA, Deng XL, . Preparation and Characterization of DLC Films by Twinned ECR Microwave Plasma Enhanced CVD for Microelectromechanical Systems (MEMS) Applications[J]. Journal of Wuhan University of Technology-Mater. Sci. Ed., 2004, 19(2): 44-47.

[16] Yoshida A, Kaburagi Y, Hishiyama Y Full Width at Half Maximum Intensity of the G Band in the First Order Raman Spectrum of Carbon Materials as a Parameter for Graphitization[J]. Carbon, 2006, 44(11): 2 333-2 335.