Relationship between Hole Distribution and Superconductivity in High-T, Tl- and Hg-Based Cuprates as Determined by X-ray Absorption Near-Edge Structure

R. S. Liu；J. M. Chen；R. G. Liu；S. F. Hu

Chinese Journal of Physics

36卷2S期（1998 / 04 / 01）

344 - 348

英文

High resolution 0 K-edge X-ray absorption near-edge-structure (XANES) spectra of the high-T, cuprates of (Tl0.5Pb0.5)Sr2(Ca1-xYx)Cu2O7 (Tl-1212) and (Hg0.5Pb0.5) Sr2(Ca1-xYx)Cu2O7 (Hg-1212) in p owder form were measured using a bulk sensitive total-fluorescence-yield technique. Near the 0 1s edge, the pre-edge peak with maxima at N 528.3 eV is ascribed to the transitions to 0 2p holes located in the CuO2 planes. The intensity of this pre-edge peak increases with increasing doping level of Ca2+ into the Y3+ sites in Tl-1212 and Hg-1212. The results can lead us to understand the hole distribution in high-?, cuprates which will give a direction to find new high-T, materials.