Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Thermal and dielectric properties of rare earth iodates

  • 50 Accesses

  • 2 Citations

Abstract

The thermal (TGA, DTA and DSC) and dielectric behaviour of all rare earth iodates (except prometheum) has been investigated. The iodates of lanthanum, cerium to europium and gadolinium to lutetium decompose differently and the activation energies for these decomposition reactions have been determined. The DSC measurements have shown that all of the anhydrous iodates undergo one or more exothermic/endothermic changes. From the nature of the DSC profiles, heat of transitions, and powder diffraction data the phase transformations of Ln (IO3)3 have been found to occur in four different ways (lanthanum, cerium to europium, gadolinium to terbium, dysprosium to lutetium). Dielectric measurements of Ln (IO3)3 at varying temperature have corroborated the observations made with DSC studies. Relatively low dielectric constants of the high-temperature phases probably indicate their centrosymmetric structures. The dielectric behaviour of noncentrosymmetric Ln (IO3)3·H2O (Ln=cerium to samarium) has been investigated in the temperature range 30 to −160° C. They have high dielectric constants (εr, ~ 1800 to 2400) at the ambient temperature and do not show significant change in the entire temperature range of investigation.

This is a preview of subscription content, log in to check access.

References

  1. 1.

    K. Nassau, J. W. Shiever, B. E. Prescott andA. S. Cooper,J. Solid State Chem. 11 (1974) 314.

  2. 2.

    K. Nassau, J. W. Shiever andB. E. Prescott,ibid. 14 (1975) 122.

  3. 3.

    S. C. Abrahams, J. L. Bernstein andK. Nassau,ibid. 16 (1976) 173.

  4. 4.

    Idem, ibid. 22 (1977) 243.

  5. 5.

    R. Liminga, S. C. Abrahams andJ. L. Bernstein,J. Chem. Phys. 62 (1975) 755.

  6. 6.

    Idem, ibid. 67 (1977) 1015.

  7. 7.

    R. Liminga andS. C. Abrahams,J. Appl. Cryst. 9 (1976) 42.

  8. 8.

    S. C. Abrahams, J. L. Bernstein, J. W. Shiever andK. Nassau,ibid. 9 (1976) 357.

  9. 9.

    J. G. Bergman, G. D. Boyd, A. Ashkin andS. Kurtz,J. Appl. Phys. 40 (1969) 2860.

  10. 10.

    E. T. Keve, S. C. Abrahams andJ. L. Bernstein,J. Chem. Phys. 54 (1971) 2556.

  11. 11.

    S. C. Abrahams, R. C. Sherwood, J. L. Bernstein andK. Nassau,J. Solid State Chem. 7 (1973) 205.

  12. 12.

    G. M. Yakunina, L. A. Alekseenko andV. V. Serebrennikov,Russ. J. Inorg. Chem. 14 (1969) 1414.

  13. 13.

    M. Harmelin,Compt. Rend. B262 (1966) 620.

  14. 14.

    B. Hajek andJ. Hardilova,J. Less-Common Met. 23 (1971) 217.

  15. 15.

    A. Ray, B. P. Ghosh andK. Nag,Thermochim. Acta 47 (1981) 105.

  16. 16.

    B. P. Ghosh, A. Ray andK. Nag,J. Mater. Sci. Lett. 2 (1983) 638.

  17. 17.

    J. L. McNaughton andC. T. Mortimer, “IRS; Physical Chemistry Series”, Vol. 10 (Butterworths, London, 1975).

  18. 18.

    B. P. Ghosh, M. Chaudhury andK. Nag,J. Solid State Chem. 47 (1983) 307.

  19. 19.

    H. H. Horowitz andG. M. Metzger,Anal. Chem. 35 (1963) 1454.

  20. 20.

    A. W. Coats andJ. P. Redfern,Nature 201 (1964) 68.

  21. 21.

    G. G. Sanyal andK. Nag,J. Inorg. Nucl. Chem. 39 (1977) 1127.

  22. 22.

    A. K. Ray, M. Chaudhury andK. Nag,Bull. Chem. Soc. Jpn. 51 (1978) 1243.

  23. 23.

    D. F. Peppard, C. A. A. Bloomquist, E. P. Horonitz, S. Leney andG. N. Mason,J. Inorg. Nucl. Chem. 32 (1970) 339.

  24. 24.

    I. Fidelis andS. Siekierski,ibid. 33 (1971) 3191.

  25. 25.

    A. Roy andK. Nag,ibid. 40 (1978) 331.

  26. 26.

    S. P. Sinha, “Systematics and Properties of the Lanthanides” (Riedel, Dordrecht, 1983).

  27. 27.

    P. Hevdig, “Dielectric Spectroscopy of Polymers” (Wiley, New York, 1977).

  28. 28.

    R. Nottenburg, K. Rajeshwar, M. Freeman andJ. Dubow,J. Solid State Chem. 28 (1979) 195.

Download references

Author information

Correspondence to K. Nag.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Ghosh, B.P., Nag, K. Thermal and dielectric properties of rare earth iodates. J Mater Sci 20, 2335–2344 (1985). https://doi.org/10.1007/BF00556063

Download citation

Keywords

  • Dielectric Constant
  • Cerium
  • Gadolinium
  • Lanthanum
  • Samarium