The Raman Spectra of Nanocomposite Clusters of Atoms in Phosphorous-Selenium Glassy State

Abstract:

We make clusters of atoms of the size of less than 1 nanometer by using the density functional theory and from that we obtain the bond lengths corresponding to the minimum energy configuration. We are able to optimize large clusters of atoms and find the vibrational frequencies for each cluster. This calculation provides us with a method to identify the clusters present in an unknown sample of a glass by comparing the experimental Raman frequency with the calculated value. We start with the experimental values of the Raman frequencies of PSe (Phosphorous-Selenium) glass. We calculate the structural parameters of PSe, P4Se, P2Se2, P4Se5, PSe4, P4Se3 clusters of atoms and tabulate the vibrational frequencies. We compare the calculated values with those measured. In this way we find the clusters of atoms present in the glass. Some times, the same number of atoms can be rearranged in a different symmetry. Hence we learn the symmetries of molecules. We find that certain symmetries are broken due to self-organization in the glassy state.

• Periodical: Advanced Materials Research (Volume 667)
• Pages: 99-103
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.667.99
• Online since: March 2013
• Authors: Ahmad Nazrul Rosli, Hasan Abu Kassim, Keshav N. Shrivastava, V. Radhika Devi
• Keywords: Cluster, Density Functional Theory (DFT), Glass, Raman Spectra, Vibrational Frequency

References

[1] V. R. Devi, M. B. Madhari, E. L. Srihari, K. N. Shrivastava, P. Boolchand, Ab initio calculation of vibrational properties of GeSI glasses, J. Non-Cryst. Solids 351 (2005) 489-494.

DOI: 10.1016/j.jnoncrysol.2005.01.041

[2] H. A. Kassim, I. A. Jalil, N. Yusof, V. R. Devi, K. N. Shrivastava, Ab initio calculation of vibrational frequencies of GePS glass, J. Non-Cryst. Solids 353, (2007) 111-118.

DOI: 10.1016/j.jnoncrysol.2006.10.006

[3] N. A. Jemali, H. A. Kassim, V. R. Devi, K. N. Shrivastava, Ab initio calculation of vibrational frequencies of GeSe glass, J. Non-Cryst. Solids 354 (2008) 1744-1750.

DOI: 10.1016/j.jnoncrysol.2007.08.053

[4] A. N. Rosli, H. A. Kassim, K. N. Shrivastava, Vibrational frequencies in AsSe glass, AIP Conf. Proc. 1017 (2008) 429-433.

[5] A. N. Rosli, H. A. Kassim, K. N. Shrivastava, Ab Initio calculation of vibrational frequencies in AsS glass and the Raman spectra, AIP Conf. Proc. 1136 (2009) 370-374.

DOI: 10.1063/1.3160167

[6] A. N. Rosli, N. A. Zabidi, H. A. Kassim, K. N. Shrivastava, Ab initio calculation of vibrational frequencies of AsO glass, J. Non-Cryst. Solids, 356 (2010) 428-433.

DOI: 10.1016/j.jnoncrysol.2009.11.041

[7] R. T. Phillips, D. Wolverson, M. S. Burdis, Y. Fang, Observation of discrete molecular structures in glassy PxSe1-x by Raman spectroscopy, Phys. Rev. Lett. 63 (1989) 2574-2577.

[8] D. G. Georgiev, P. Boolchand, H. Eckert, M. Micoulaut, K. Jackson, The self-organized phase of bulk PxSe1 – x glasses, Europhys. Lett. 62 (2003) 49.

DOI: 10.1209/epl/i2003-00361-2

[9] D. G. Georgiev, M. Mitkova, P. Boolchand, G. Brunklaus, H. Eckert, M. Micoulaut, Molecular structure, glass transition temperature variation, agglomeration theory, and network connectivity of binary P-Se glasses, Phys. Rev. B 64, (2001).

DOI: 10.1103/physrevb.64.134204

[10] W. Kohn, L. J. Sham, Self-Consistent Equations Including Exchange and Correlation Effects, Phys. Rev, 140 (1965) A1133-A1138.

DOI: 10.1103/physrev.140.a1133