INCREASING OF T-C IN THE NEW HTSC HGBA2CUO4+DELTA PROMOTED BY DEFECTS

X-ray powder diffraction of the new high-Tc superconducting phase (Hg1 -xCux) Ba2CuO4+delta, where x = 0.17 with the onset superconducting tr ansition at 125 K was used to define coordinates, isotropic thermal pa rameters of the atoms and for interatomic distances calculation. For t he first time in the Hg-based cuprate superconductors was observed the occurrence of the optical second harmonic generation (SHG) of YAG-Nd laser, which gives evidence for the appearance the asymmetric electron ic density, correlated with an increase of superconducting transition temperature. It is assumed that the increase of T-c associated with th e formation of two (CuO2) layers in the average unit cell at the subst itution of the part atoms Cu for Hg and the partial occupancy of the ( 1/2 0 0) sites by oxygen atoms.