Journal of Materials Science

, Volume 30, Issue 14, pp 3720–3729 | Cite as

The optical properties and a.c. conductivity of magnesium phosphate glasses

  • S. K. J. Al-Ani
  • I. H. O. Al-Hassany
  • Z. T. Al-Dahan


Magnesium phosphate [X MgO-(100−X) P2O5] glasses in the composition range [X=20, 25, 30, 40, 45, 50 mol %] have been made. The optical properties and a.c. conductivities were measured and their amorphous nature confirmed by X-ray diffraction technique. The variation of relative density with x was anomalous. In the ultraviolet/visible regions it was found that the fundamental absorption edge is a function of glass compositions and lower absorption coefficients, α(Ω) follow the so-called Urbach edge. At lower absorption levels (1<α<104cm−1), the width of the tail of localized states in the band gap, Eg, did not vary significantly with glass composition and lay in the range (0.26–0.343) eV. In the high absorption region (α(Ω)>104 cm−1), the behaviour of α(Ω) suggests that there are two different transition energies for electrons in k-space, namely direct allowed transitions and non-direct transitions. In the infrared region at wavelengths λ=2.5–30 Μm, the transmission spectrum has four absorption bands. Using the Kramers-Kronig theory, the optical constants (refractive index n and extinction coefficient k) have been determined from the transmission spectrum. The a.c. conductivity, σ(Ω), real and imaginary dielectric constants, ε1, ε2, and loss factor, tan δ, have been determined at room temperature in the frequency region, Ω = 2×104−106 Hz. It has previously been established theoretically that σ(Ω)∼Ωs and s was found to be in the range 0.64–0.73, depending on glass composition.


Refractive Index Dielectric Constant Relative Density Transmission Spectrum Loss Factor 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    N. F. Mott and E. A. Davis, “Electronic Processes in Non-Crystalline Materials”, (Clarendon Press, Oxford, 1979).Google Scholar
  2. 2.
    S. P. Edirisinghe and C. A. Hogarth, J. Mater. Sci. Lett. 8 (1989) 789.CrossRefGoogle Scholar
  3. 3.
    S. K. J. AL-ANI, PhD thesis, Brunel University (1984).Google Scholar
  4. 4.
    S. K. J. Al-Ani and A. A. Higazy, J. Mater. Sci. 26 (1991), 3670.CrossRefGoogle Scholar
  5. 5.
    E. Kordes, W. Vogel and R. Feterowsky, Z. Elektrochem, 57 (1953) 282.Google Scholar
  6. 6.
    T. Okura, K. Yamashita and T. Kanazawa, Phys. Chem. Glasses 29 (1988) 13.Google Scholar
  7. 7.
    F. Urbach, Phys. Rev. 92 (1953) 1324.CrossRefGoogle Scholar
  8. 8.
    J. Tauc, R. Gigorovici and A. Vancu, Phys. Status Solidi 15 (1966) 627.CrossRefGoogle Scholar
  9. 9.
    E. A. Davis and N. F. Mott, Philos. Mag. 22 (1970) 903.CrossRefGoogle Scholar
  10. 10.
    E. A. Davis, J. Non-Cryst. Solids 4 (1970) 107.CrossRefGoogle Scholar
  11. 11.
    S. K. J. Al-ani and C. A. Hogarth, ibid. 69 (1984) 167.CrossRefGoogle Scholar
  12. 12.
    Idem, Phys. Status Solidi (a) 87 (1985) K65.CrossRefGoogle Scholar
  13. 13.
    C. A. Hogarth and M. Y. Nadeem, ibid. 68 (1981) K181.CrossRefGoogle Scholar
  14. 14.
    S. K. J. Al-Ani, Ki. Arshak and C. A. Hogarth, J. Mater. Sci. 19 (1984) 1737.CrossRefGoogle Scholar
  15. 15.
    S. K. J. Al-Ani, C. A. Hogarth and M. Ilyas, J. Mater. Sci. Lett. 3 (1984) 391.CrossRefGoogle Scholar
  16. 16.
    G. R. MORIDI and C. A. HOGARTH, in “Proceedings of the 7th International Conference on Amorphous and Liquid Semiconductors”, Edinburgh, edited by W. E. Spear (1977) 688.Google Scholar
  17. 17.
    S. K. J. Al-Ani, C. A. Hogarth and R. A. Elmalawany, J. Mater. Sci. 20 (1985) 661.CrossRefGoogle Scholar
  18. 18.
    S. K. J. Al-ani and C. A. Hogarth, ibid. 20 (1985) 1185.CrossRefGoogle Scholar
  19. 19.
    G. W. Anderson and W. D. Compton, J. Chem. Phys. 52 (1970) 6166.CrossRefGoogle Scholar
  20. 20.
    V. Vorliček, M. Lavetova, S. K. Pavlov and L. Pajasova, J. Non-Cryst. Solids 45 (1981) 289.CrossRefGoogle Scholar
  21. 21.
    I. D. Dow and D. Redfield, Phys. Rev. B 5 (1972) 594.CrossRefGoogle Scholar
  22. 22.
    J. TAUC, in “Optical Properties of Solids”, edited by F. Abeles (Amsterdam, 1970) p. 277.Google Scholar
  23. 23.
    H. A. Kramers, Atticong. Int. Fis. Comr. 2 (1927) 545.Google Scholar
  24. 24.
    Idem, Phys. Z. 30 (1929) 521.Google Scholar
  25. 25.
    R. De L. Kronig, J. Opt. Soc. Am. 12 (1926) 547.CrossRefGoogle Scholar
  26. 26.
    Idem, Phys. Rev. 30 (1929) 521.Google Scholar
  27. 27.
    J. Tauc, Prog. Semicond. 9 (1965) 87.Google Scholar
  28. 28.
    J. Tauc, (ed.), “Amorphous and Liquid Semiconductors” (Plenum Press, London, 1974).Google Scholar
  29. 29.
    J. Wong and C. A. Angell, “Glass structure by spectroscopy” (Marcel Dekker, New York, 1977).Google Scholar
  30. 30.
    I. J. DAYAWANZA, PhD thesis, University of Wales (1977).Google Scholar
  31. 31.
    T. R. Steryer, L. Day and D. R. Hufman, Appl. Opt. 13 (1974) 1586.CrossRefGoogle Scholar
  32. 32.
    Q. S. MAJEED, PhD thesis, University of Wales, (1990).Google Scholar
  33. 33.
    S. R. Elliot, Philos. Mag. 36 (1977) 1291.CrossRefGoogle Scholar
  34. 34.
    A. Doi, J. Mater. Sci. Lett. 6 (1987) 648.CrossRefGoogle Scholar
  35. 35.
    W. Matz, D. Stachel and E. A. Goremychkin, J. Non-Cryst. Solids 101 (1988) 80.CrossRefGoogle Scholar
  36. 36.
    M. Ashizuka, E. Ishida, S. Uto and R. C. Bradt, ibid. 104 (1988) 316.CrossRefGoogle Scholar
  37. 37.
    E. Matsubara, T. Kawazoe, Y. Waseda, M. Ashizuka and E. Isida, J. Mater. Sci. 23 (1988) 547.CrossRefGoogle Scholar

Copyright information

© Chapman & Hall 1995

Authors and Affiliations

  • S. K. J. Al-Ani
    • 1
  • I. H. O. Al-Hassany
    • 1
  • Z. T. Al-Dahan
    • 1
  1. 1.Department of PhysicsCollege of Education for Women, University of Baghdad, JadiryaBaghdadIraq

Personalised recommendations