Department of Physical Chemistry, University of Nijmegen, Toernooiveld, 6525 ED Nijmegen, The Netherlands
Abstract:
The electric quadrupole interactions at the octahedral, tetrahedral, and dodecahedral sites in the Eu3?ySc2+yFe3O12 (0 ≤ y ≤ 0.5) garnet system were studied with 57Fe and 151Eu Mössbauer spectroscopy. The electric field gradient tensor at the three sites was calculated using a monopole-point-dipole model. It is shown that the dipole contribution to the electric field gradient tensor is not negligible even for very small values of the oxygen dipole polarizability. The importance of the overlap and second-order 4f contributions is discussed.