INVESTIGADORES
RENTERIA Mario
artículos
Título:
Hyperfine interactions at 181 Hf ( --> 181 Ta ) impurities implanted in Er 2 O 3 and Gd 2 O 3 : structural and electronic dependence of the EFG in bixbyite sesquioxides
Autor/es:
L.A. ERRICO; M. RENTERÍA; A.F. PASQUEVICH; A.G. BIBILONI; K. FREITAG
Revista:
EUROPEAN PHYSICAL JOURNAL B - CONDENSED MATTER
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2001 vol. 22 p. 149 - 156
ISSN:
1434-6028
Resumen:
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 Er 2 O 3 and Gd 2 O 3 . The TDPAC experiments were
performed in air in the temperature range 300-1073 K (in the case of Er 2
O 3 ) and 300-1173 K (in the case of Gd 2 O 3 ). 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.