Study of the Electric Field Gradient in EuBa2 Cu3 07(delta) (Delta Approx. =0 and delta Approx. =1)

摘要

We have measured the quadrupole interaction parameter and the asymmetry coefficient at the /sup 151/Eu Moessbauer nucleus for EuBa/sub 2/Cu/sub 3/0/sub 7-delta/, delta approx. =0 and delta approx. =1. The measurements have been extended up to 420 K and 600 K respectively. From the temperature dependence of the electric field gradient parameter V/sup Eu/ /sub zz/ and the isomer shift we deduce that the contribution of the excited electronic state of Eu/sup 3+/ to the measured parameters is stronger in the superconducting than in the semiconducting oxide. (ERA citation 14:017791)