Abstract :
X-ray-absorption near-edge structure (XANES) measurements of the O–K and Cu–L edges of the series (Sr1−xLax)CuO2 with x=0 and 0.1 have been performed. The appearance of the Cu2p3d104s state in (Sr0.9La0.1)CuO2 is an indication of formal Cu+ formation which provides a direct evidence for n-type superconductivity in this composition.
