EFG of 111Cd at the Cu1-site in YBa 2Cu 3O 7 and in YBa 2Cu 3O 6 measured with the PAC-technique

Abstract

111In was implanted at 400 keV into polycrystalline YBa 2Cu 3O 7 into bulk samples prepared via the citrate-synthesis and into an YBa 2Cu 3O 7 single crystal. In perturbed angular correlation (PAC) measurements most of the probe atoms sense an electric field gradient (EFG) which had already been attributed to 111Cd at the Cu1-site surrounded by four oxygen atoms. The tetragonal → orthorhombic phase transition was repeated cyclically with 111In at this site. In the tetragonal phase (YBa 2Cu 3O 6) 111Cd sees a different EFG, which is quite similar to the one observed in the linear bond (oxygen-metal-oxygen) in Cu 2O and Ag 2O. This gives further evidence that most of the implanted 111In atoms are incorporated at the Cu1-site of YBaCuO.