TY - JOUR
T1 - MEM analysis on electron density distribution of superconductors, Pb2Sr2Y0.90Sr0.10Cu 3O8, Pb2Sr2Y1-xCaxCu3O 8 (x=0.25 and 0.41) and Pb2Sr2Ho0.64Ca0.36Cu 3O8
AU - Ono, Yasuhiro
AU - Bungo, Akihiro
AU - Noji, Takashi
AU - Koike, Yoji
AU - Kajitani, Tsuyoshi
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1998/5
Y1 - 1998/5
N2 - Detailed crystal structures of high-Tc superconductors Pb2Sr2Y0.90Sr0.10Cu 3O8, Pb2Sr2Y1-xCaxCu3O 8 (x=0.25 and 0.41) and Pb2Sr2Ho0.64Ca0.36Cu 3O8 were successfully determined by means of single crystal X-ray diffraction at room temperature. Space symmetry changes from C2/m (x=0.10 and 0.25) to Cmmm (x=0.36 and 0.41) with increasing divalent cation concentration, x. Their electron density distributions are determined by means of the maximum entropy method (MEM). Two- or four-splitting oxygen peaks clearly appear in the electron density maps of PbO plane, which is consistent with oxygen disorder models introduced to the present structure determination. In the electron density maps of monovalent copper plane, no peak corresponding to excess oxygens was observed at the 1 × 103 e/nm3 contour level. In the vicinities of divalent copper in the conducting plane, some anomalous electron density distribution is represented in the yttrium compounds.
AB - Detailed crystal structures of high-Tc superconductors Pb2Sr2Y0.90Sr0.10Cu 3O8, Pb2Sr2Y1-xCaxCu3O 8 (x=0.25 and 0.41) and Pb2Sr2Ho0.64Ca0.36Cu 3O8 were successfully determined by means of single crystal X-ray diffraction at room temperature. Space symmetry changes from C2/m (x=0.10 and 0.25) to Cmmm (x=0.36 and 0.41) with increasing divalent cation concentration, x. Their electron density distributions are determined by means of the maximum entropy method (MEM). Two- or four-splitting oxygen peaks clearly appear in the electron density maps of PbO plane, which is consistent with oxygen disorder models introduced to the present structure determination. In the electron density maps of monovalent copper plane, no peak corresponding to excess oxygens was observed at the 1 × 103 e/nm3 contour level. In the vicinities of divalent copper in the conducting plane, some anomalous electron density distribution is represented in the yttrium compounds.
KW - Electron density distribution
KW - High-t superconductor
KW - Maximum entropy method (mem)
KW - Pbsrlncacuo
KW - X-ray diffraction
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U2 - 10.2320/matertrans1989.39.562
DO - 10.2320/matertrans1989.39.562
M3 - Article
AN - SCOPUS:0032067302
VL - 39
SP - 562
EP - 569
JO - Materials Transactions
JF - Materials Transactions
SN - 1345-9678
IS - 5
ER -