X-ray photo-emission studies of Cu1−xTlxBa2Ca3Cu4O12−y superconductor thin films

摘要: Abstract X-ray photo-emission spectroscopy (XPS) studies of Cu 1− x Tl Ba 2 Ca 3 4 O 12− y superconductor thin films have been carried out for understanding the mechanism superconductivity and to find reasons increase zero resistivity critical temperature T c ( R  = 0) with post-annealing in a nitrogen atmosphere. It is observed from these that reduction charge state thallium source doping carriers CuO planes. The reduced (i.e. 1+ ) promotes lower oxygen concentration reservoir layer, which possibly results movement electrons conducting higher density planes optimizes hole “ n p ” 4− δ layer also supported by shift 3d 5/2 3/2 XPS lines binding energies Moreover, valance band spectrum suggested electronic states changes nitrogen, becomes increased Fermi-vector K F Fermi-velocity V increases final compound.