Asian Journal of Materials Science1996-3394xxxx-xxxxAsian Network for Scientific Information10.3923/ajmskr.2010.204.210ManojB. KunjomanaA.G. 4201024In this study, Raman spectra in the 400 to 1800 cm-1 region were obtained for two different coal samples. The bands observed at 601 and 569 cm-1 were attributed to presence of Halloysite which was shifted to lower wave number with leaching. Intense bands observed at 569-640 cm-1 could also correspond to ring breathing vibration. Band due to Si-O perpendicular vibration is observed at 1090 cm-1 and is disappeared with HF leaching. The graphite band (1580 cm-1) and the defect band (1350 cm-1) were observed in the sample. Intensity of graphite band (G) was stronger in bituminous coal than sub-bituminous coal, where as the defect band was stronger in sub-bituminous coal with leaching. Presence of D-band was an indication of condensed Benzene rings in amorphous carbon and was comparatively stronger in sub-bituminous coal. Carbonyl bands were stronger in sub-bituminous coal than bituminous coal. The relatively strong band near 1695 cm-1 was attributed to carboxylic acid and relatively weak band at 1670 cm-1 was assigned to ketonic structures. Sub-bituminous coal sample was showing moderately higher absorption than bituminous coal. Samples having higher oxygen content had intense absorption band of carbonyl group compared to samples having lower oxygen content.]]>Friedel, R.A. and G.L. Carlson,197251194198Frost, R.L., P.M. Fredericks and J.R. Bartlett,199349667674Guedes, A., B. Valentim, S. Prieto, S. Rodrigues and F. Noronha,20102010Ishii, M., T. Shimanouchi and M. Nakahira,19671387392Jelicka, J., H.G.M. Edwards and S.E.J. Villar,200665229234Johnson, C.A., J.W. Patrick and K.M. Thomas,19866512841290Nemanich, R.J. and S.A. Solin,197920392401Schwan, J., S. Ulrich, V. Batori, H. Enrhardt and S.R.P. Silva, 199680440447Starsinic, M., Y. Otake, Jr. P.L. Walker, P.C. Painter-Fuel,19846310021007Tuinstra, F. and J.L. Koenig,19705311261130Wang, Y., D.C. Alsmeyer and R.L. McCreery,19902557563Li, X., J.I. Hayashi and C.Z. Li,20068517001707