Ap. Menushenkov et al., RADIATIVE DEFECTS STRUCTURE IN HTSC THIN-FILMS - POLARIZED XAS STUDY, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 97(1-4), 1995, pp. 151-154
Copper K-edge polarized EXAFS and XANES data of YBa2Cu3O6.9 and Nd1.85
Ce0.15CuO4 films indicate that He+ ion irradiation induces the radiati
ve defects that are situated in the chains: (Cu-O-Nd(Ce) for Nd1.85Ce0
.15CuO4 and Cu(1)-O(1), Cu(1)-O(4)-Cu(2) for YBa2Cu3O6.9), rather than
in the CuO2 (2D) plane. Static disorder with the typical displacement
from primary plane site up to 0.1 Angstrom for the O(2) environments
was observed for Nd1.85Ce0.15CuO4. In addition the oxygen deficiency i
n O(1) sites and the disorder of apical O(4) sites were obtained for Y
Ba2Cu3O7-x. At the same time we have not found any local changes in-pl
ane structure after irradiation for both compounds. The data obtained
point out the essential role of the ordering in the chains for 2D plan
e coupling both for hole-type and electron-type high temperature super
conductors.