Hyperfine Interactions

, Volume 30, Issue 1, pp 9–16 | Cite as

The thermal behaviour of the quadrupole hyperfine interaction in (NH4)2HfF6

  • J. A. Martínez
  • P. C. Rivas
  • M. C. Caracoche
  • A. M. Rodríguez
  • A. R. López García
  • S. Spinelli
Article

Abstract

A TDPAC investigation has been accomplished on (NH4)2 HfF6 between 14 and 620 K. A phase transition was observed below 390 K. The low temperature phase is characterized by two non-equivalent sites for hafnium atoms in a 1∶1 ratio. The high temperature phase, on the other hand, is depicted by a unique quadrupole interaction. Above 400 K, the compound decomposes successively to NH4 HfF5, NH4 Hf2F9 and HfF4. An enthalpy of 76±4 kJ/mol could be determined for the (NH4)2 HfF6→NH4 HfF5+NH4F chemical reaction. The hyperfine interaction and thermal evolution of (NH4)2 HfF6 was found to be quite similar to that of (NH4)2 ZrF6.

Keywords

Thin Film Enthalpy Phase Transition Thermal Behaviour Hafnium 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    L. Mayer, E. Bodenstedt and C. Günther, Z. Phys. 177(1964)28.CrossRefGoogle Scholar
  2. [2]
    E. Gerdau, J. Wolf, H. Winkler and J. Braunsfurth, Proc. Roy. Soc. A311(1969)197.ADSGoogle Scholar
  3. [3]
    E. Gerdau, B. Scharnberg and H. Winkler, in:Hyperfine Interactions in Excited Nuclei (Gordon and Breach, New York, 1971) p. 861.Google Scholar
  4. [4]
    M.A. Mikhailov, D.G. Epov and E.G. Rakov, Russ. J. Inorg. Chem. 18(1973)56.Google Scholar
  5. [5]
    A.M. Rodríguez, J.A. Martínez, M.C. Caracoche, P.C. Rivas and A.R. López García, Hyp. Int. 14(1983)227.CrossRefGoogle Scholar
  6. [6]
    A.M. Rodríguez, J.A. Martínez, M.C. Caracoche, P.C. Rivas, A.R. López García, and S. Spinelli, J. Chem. Phys. 82(1985)1271.CrossRefADSGoogle Scholar
  7. [7]
    B. Gaudreau, Rev. Chim. Minérale 2(1965)1.Google Scholar
  8. [8]
    H. Hull and A.G. Turnbull, J. Inorg. Nucl. Chem. 29(1967)951.CrossRefGoogle Scholar
  9. [9]
    J.A. Martínez, M.C. Caracoche, A.M. Rodríguez, P.C. Rivas and A.R. López García, Hyp. Int. 14(1983)135.CrossRefGoogle Scholar
  10. [10]
    J.A. Martínez, M.C. Caracoche, A.M. Rodríguez, P.C. Rivas and A.R. López García, Chem. Phys. Lett. 102(1983)277.CrossRefADSGoogle Scholar

Copyright information

© J.C. Baltzer A.G., Scientific Publishing Company 1986

Authors and Affiliations

  • J. A. Martínez
    • 1
  • P. C. Rivas
    • 1
  • M. C. Caracoche
    • 1
  • A. M. Rodríguez
    • 1
  • A. R. López García
    • 1
  • S. Spinelli
    • 2
    • 3
  1. 1.Laboratorio de Interacciones Hiperfinas, Facultad de Ciencias ExactasUniversidad Nacional de La Plata, CC 67La PlataArgentina
  2. 2.Laboratorio de Rayos X, Facultad de Ciencias ExactasUniversidad Nacional de La Plata, CC 67La PlataArgentina
  3. 3.Departmento de Física, Facultad de Ciencias ExactasUniversidad Nacional de La Plata, CC 67La PlataArgentina

Personalised recommendations