Authors: H.S. Sahibudeen, M.A. Navacerrada and J.V. Acrivos
Affilation: San Jose State University, United States
Pages: 573 - 576
Keywords: cuprates, SCF calculations, superconductivity, XRD, PLD
Self consistent field (SCF) calculations carried out at San José State University (using MOLECOLE Linux codes) for a nano-particle of 18 molecules of T’-Nd2CuO4 explain the dxy symmetry for preferred superconductivity in the ab plane. These indicate that 1D conductivity is induced along the ab diagonal when there is a periodic lattice distortion (PLD) at site R: uexp(i(2pR.q+f)) (measured in X-ray diffraction (XRD)) of wave vector q and amplitude u. XRD and X-ray absorption (XAS) measurements were done (at the Stanford Synchrotron Radiation Laboratory (SSRL) and at the Lawrence Berkeley National Laboratory (LBNL-ALS)) on 50 nm c-axis oriented YBCO films (deposited on single crystal SrTiO3 and bi-crystals with a 24DEG grain boundary (GB) at the Complutense University). Understanding structure and distortions of YBCO films is important for device fabrication.