Actinide Incorporation Into Pristine and Stabilized Zirconia Phases


Actinide Incorporation Into Pristine and Stabilized Zirconia Phases

Eibl, M.; Huittinen, N.; Stumpf, T.

In the present study the stabilizing effect of the actinide analogue ion Eu3+ on zirconia in dependency of the molar fraction and the influence of the trivalent stabilizer cation radius on zirconia solids in a series of Ln3+ (Ln3+ = La, Sm, Gd, Tb, Lu) co-doped with Eu3+ is investigated using a combination of x-ray powder diffraction (PXRD) and time-resolved laser fluorescence spectroscopy (TRLFS). PXRD is employed to gain an insight into the zirconia crystal structure in the presence of Eu3+ and/or Ln3+ and to identify the various zirconia phases (m, t, and c).
For the material with 2% Eu3+ mainly the monoclinic structure is to be seen in the PXRD pattern. A sample with 8% Eu3+ can be assigned to the tetragonal structure while at an incorporation percentage of 22% Eu3+ the cubic phase is predominant. The broadness of the TRLFS emission peaks of the sample with 2% Eu3+ speaks for a poorly ordered solid or Eu3+ incorporation on a very distorted host cation site. The 7F1 as well as the 7F2 band show a strong band splitting which correlates to low crystal symmetry. The band splitting of both samples with higher europium content is reduced because of a higher symmetry as could be seen in the XRD pattern. To prove the transferability of the lanthanide to actinides selected samples will be prepared and studied using Cm3+ as dopant.
The effect of different stabilizers on the nucleation process has been studied using a combination of the crystal truncation diffraction (CTR) and the resonant anomalous x-ray scattering techniques (RAXR) using synchrotron radiation at the European synchrotron radiation facility (ESRF) in Grenoble.
The results of these ongoing investigations will be presented in detail at the conference.

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  • Poster
    16th International Conference on the Chemistry and Migration Behaviour of Actinides and Fission Products in the Geosphere, 10.-15.09.2017, Barcelona, Spanien

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Publ.-Id: 25317