Enhancement of the superconducting critical temperature of Sr2CuO3+d up   to 95K by ordering dopant atoms
  We address the question of whether the superconducting transition temperature (Tc) of high-Tc cuprates is enhanced when randomly distributed dopant atoms form an ordered array in the charge reservoir layers. This study is possible for the Sr2CuO3+d superconductor with K2NiF4-type structure in which oxygen atoms only partially occupy the apical sites next to the CuO2 planes and act as hole-dopants. We show that remarkable Tc enhancement up to 95K in this mono CuO2 layered HTS is associated with the apical oxygen ordering, not to the hole concentration change. The result points a route toward further enhancement of Tc in cuprate superconductors. 
Q.Q.Liu, H.Yang, X.M.Qin, Y.Yu, L.X.Yang, F.Y.Li, R.C.Yu, C.Q.Jin, S.   Uchida