A study was made of the local chemical environment of Cu in this material. It was found that EXAFS data were dominated by coherent multiple scattering in the CuO2 planes, where Cu was present in an almost undistorted square-planar coordination. By subtracting the spectra of samples which had been annealed in O partial pressures of 1 and 10-6atm., evidence was obtained on O interstitials in the region of p-type conductivity.

P.Ghigna, G.Spinolo, A.Filipponi, A.V.Chadwick, P.Hanmer: Physica C, 1995, 246[3-4], 345-50