TY - JOUR
T1 - Studies of the Cu-O bond in (Pb, Cd)-1212 and (Pb, Cd)-1201 cuprates by X-ray photoelectron spectroscopy
AU - Yu, W. J.
AU - Mao, Z. Q.
AU - Tian, M. L.
AU - Wang, Y.
AU - Zhou, G. E.
AU - Zhang, Y. H.
PY - 1996/1
Y1 - 1996/1
N2 - It is shown that in (Pb0.5Cd0.5)Sr2(Y0.5Ca 0.5)Cu2O7 and (Pb0.5Cd0.5)SrLaCuO5 cuprates, where Cu2+ ions are in pyramidal and octahedral geometry with five and six neighboring oxygens, respectively, the Cu2p3/2(2p53d10L) XPS core line is broader than that in Nd2CuO4 where Cu2+ ions are in a square planar geometry with four coordination oxygen ions, and that for (Pb0.5Cd0.5)SrLaCuO5 is the broadest. To explain these changes in the XPS Cu2p3/2 main line, two different charge transfer mechanisms from the O2p to the Cu3d orbitals are considered. For the square planar geometry (CuO4) only the O2px, y → Cu3dx2-y2 charge transfer is allowed, whereas for pyramidal and octahedral geometries an additional apical O2pz → Cu3d3z2-r2 transition could take place, and in octahedral geometry the latter transition is more significant. The valence band spectra of the cuprates also confirm this proposition.
AB - It is shown that in (Pb0.5Cd0.5)Sr2(Y0.5Ca 0.5)Cu2O7 and (Pb0.5Cd0.5)SrLaCuO5 cuprates, where Cu2+ ions are in pyramidal and octahedral geometry with five and six neighboring oxygens, respectively, the Cu2p3/2(2p53d10L) XPS core line is broader than that in Nd2CuO4 where Cu2+ ions are in a square planar geometry with four coordination oxygen ions, and that for (Pb0.5Cd0.5)SrLaCuO5 is the broadest. To explain these changes in the XPS Cu2p3/2 main line, two different charge transfer mechanisms from the O2p to the Cu3d orbitals are considered. For the square planar geometry (CuO4) only the O2px, y → Cu3dx2-y2 charge transfer is allowed, whereas for pyramidal and octahedral geometries an additional apical O2pz → Cu3d3z2-r2 transition could take place, and in octahedral geometry the latter transition is more significant. The valence band spectra of the cuprates also confirm this proposition.
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U2 - 10.1002/pssb.2221930116
DO - 10.1002/pssb.2221930116
M3 - Article
AN - SCOPUS:0030534518
VL - 193
SP - 151
EP - 154
JO - Physica Status Solidi (B): Basic Research
JF - Physica Status Solidi (B): Basic Research
SN - 0370-1972
IS - 1
ER -