Advertisement

Applied Magnetic Resonance

, Volume 12, Issue 2–3, pp 375–387 | Cite as

Pulsed EPR spectroscopy of Gd3+ centers in Ca1−x R x F2+x (R=La, Y) mixed crystals

  • A. B. Arauzo
  • R. Alcalá
  • P. J. Alonso
Article

Abstract

A study of Gd3+ centers in Ca1−x R x F2+x (R=La, Y) crystals using pulsed EPR spectroscopy is presented. The echo-induced EPR (ESE-EPR) spectrum shows, besides the signal of slightly perturbed cubic Gd3+ centers, a broad signal at g≈2 due to Gd3+ centers at low symmetry sites. To describe the effects of R3+ ions on the EPR Gd3+, a model, including cubic and linear R3+−2F i centers, is developed. Its predictions are compared with the experimental results. The composition dependence of the EPR signal due to slightly perturbed cubic Gd3+ centers in mixed Ca1−x R x F2+x crystals is explained taking into account the different clustering tendency in La and Y crystals. Moreover, the formation of mixed clusters involving R3+ and Gd3+ ions is proposed for both series of samples. A greater clustering trend is found in the Y crystals than in the La ones. Gd3+ ions are found to be a “non innocent” paramagnetic probe for structural studies in these mixed crystals.

Keywords

Mixed Crystal Electron Spin Echo Rare Earth Content Mixed Cluster Spin Hamiltonian 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    Greis O., Haschke J.M. in: Handbook on the Physics and Chemistry of Rare Earths (Gschneider K.A. Jr., Eyring L., eds.), p. 387 and ff. vol. 5, chap. 45, 1982.Google Scholar
  2. [2]
    Sobolev B.P.: Butl. Soc. Cat. Cien.12, 275 (1991)Google Scholar
  3. [3]
    Sobolev B.P., Fedorov P.P.: Inorganic Materials29, 382 (1993)Google Scholar
  4. [4]
    Sobolev B.P. in: Multicomponent Crystals Based on Heavy Metal Fluorides for Radiation Detectors (Sobolev B.P., ed.), p. 9. Barcelona: Institut d’Studis Catalans 1994.Google Scholar
  5. [5]
    Laredo E.: Proceedings of the XII International Conference on Defects in Insulating Materials. Germany: Schlob Nordkirche. Singapore: World Scientific 1993.Google Scholar
  6. [6]
    den Hartog H.W. in: Defects and Disorder in Crystalline and Amorphous Solids (Catlow C.R.A., ed.), pp. 435–455. NATO ASI Series C418. Dordrecht: Kluwer 1994.Google Scholar
  7. [7]
    den Hartog H.W.: Phys. Rev. B27, 20 (1983)CrossRefADSGoogle Scholar
  8. [8]
    den Hartog H.W., Pen K.F., Meuldijk J.: Phys. Rev. B28, 6031 (1983)CrossRefADSGoogle Scholar
  9. [9]
    Alcalá R., Alonso P.J., Sobolev B.: Rad. Eff. Def. Solids119–121, 243 (1991)CrossRefGoogle Scholar
  10. [10]
    Laredo E., Díaz M., Suarez N., Bello A.: Phys. Rev B46, 11515 (1992)CrossRefGoogle Scholar
  11. [11]
    Capelleti R., Okuno E., Mathews G.E., Crawford J.H.: Phys. Status Solidi A47, 617 (1978)CrossRefGoogle Scholar
  12. [12]
    Gorlov A.D., Potapov A.P., Levin L.I., Ulanov V.A.: Sov. Phys. Solid State33, 801 (1991)Google Scholar
  13. [13]
    Barkuijsen H., De Beer R., Bovée V.M.M.J., Van Ormondt D.: J. Magn. Reson.61, 465 (1985)Google Scholar
  14. [14]
    Barkuijsen H., De Beer R., Van Ormondt D.: J. Magn. Reson.64, 343 (1987)Google Scholar
  15. [15]
    Baker J.M., Bluck L.J.C.: Condens. Matter2, 7537 (1990)CrossRefADSGoogle Scholar
  16. [16]
    Andeen C.G., Fontanella J.J., Wintersgill M.C., Welcher P.J., Kimble R.J. Jr., Matthews G.E. Jr.: Solid State Phys.14, 3557 (1981)CrossRefADSGoogle Scholar
  17. [17]
    Golstein H.: Classical Mechanisms, chap. 5. Reading, MA: Addison-Wesley 1959.Google Scholar
  18. [18]
    Shanon R.D., Prewitt C.T.: Acta Cryst. B25, 925 (1969)CrossRefGoogle Scholar
  19. [19]
    Andeen C., Matthews G.E. Jr., Smith M.K., Fontanella J.: Phys. Rev. B19, 10 (1979)CrossRefGoogle Scholar
  20. [20]
    Laredo E., Suárez N., Bello A., Puma M.: Solid State Ionics37, 103 (1990)CrossRefGoogle Scholar

Copyright information

© Springer 1997

Authors and Affiliations

  • A. B. Arauzo
    • 1
  • R. Alcalá
    • 1
  • P. J. Alonso
    • 1
  1. 1.Instituto de Ciencia de Materiales de Aragón(Consejo Superior de Investigationes Cientificas-Universidad de Zaragoza)ZaragozaSpain

Personalised recommendations