https://doi.org/10.1007/PL00011141
Hyperfine interactions at 181Hf(→181Ta) impurities implanted in Er2O3 and Gd2O3: structural and electronic dependence of the EFG in bixbyite sesquioxides
1
Departamento de Física e Instituto de Física La Plata (IFLP, CONICET), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC 67, 1900 La Plata, Argentina
2
Laboratoire pour l'Utilisation du Rayonnement Électromagnétique (LURE), Centre Universitaire
Paris-Sud, bâtiment 209 A, BP 34, 91898, Orsay Cedex, France
3
Institut für Strahlen-und Kernphysik (ISKP) der Universität Bonn, Nussallée 14-16, 53115
Bonn, Germany
Corresponding author: a renteria@venus.fisica.unlp.edu.ar
Received:
29
December
2000
Revised:
8
March
2001
Published online: 15 July 2001
The time-differential-perturbed γ-γ angular-correlation technique (TDPAC) with ion-implanted 181Hf tracers has been applied to study the hyperfine interactions of 181Ta impurities in the cubic bixbyite structure of Er2O3 Gd2O3. The TDPAC experiments were performed in air in the temperature range 300-1073 K (in the case of Er2O3) and 300-1173 K (in the case of Gd2O3). Three electrical-quadrupole interactions were found in each oxide in the whole studied temperature range. Two of them were attributed to the electric-field gradients (EFG) acting on 181Ta probes substitutionally located on the two nonequivalent free-of-defects cation sites of the bixbyite structure. The EFG results are compared with predictions of the point-charge model and discussed together with previous results obtained with the probes 111Cd and 181Ta in other isomorphous sesquioxides. The temperature dependence of the hyperfine parameters for both oxides is also discussed in terms of dilatometric expansion data.
PACS: 61.72.Ww – Doping and impurity implantation in other materials / 76.80.+y – Mössbauer effect; other gamma-ray spectroscopy / 71.70.Jp – Nuclear states and interactions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001