Polarized XAS spectroscopy of HTSC thin films

We discuss some details of polarized XAS spectroscopy of HTSC films. To illustrate the possibilities of the method, an analysis of the influence of He+ irradiation on electronic and local structures both for hole-type YBa2Cu8O7−x (YBCO) and electron-type Nd1.85Ce0.15CuO4 (NCCO) HTSC is presented. Copper K-edge polarized EXAFS and XANES data indicate that He+ ion irradiation induces radiative defects that are situated in the chains (CuONd(Ce) for NCCO and Cu(1)O(1), Cu(1)O(4)Cu(2) for YBCO) rather than in the CuO2 (2D) plane. The data obtained point out the essential role of the ordering in the chains for 2D plane coupling both for hole-type and electron-type high temperature superconductors.