THE INFLUENCE OF INTERNAL STRAIN ON THE CHARGE-DISTRIBUTION AND SUPERCONDUCTING TRANSITION-TEMPERATURE IN BA2YCU3OX

被引:100
作者
BROWN, ID
机构
[1] Institute for Materials Research, McMaster University, Hamilton
关键词
D O I
10.1016/0022-4596(91)90181-G
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
The bond lengths in Ba2YCu3Ox expected from chemical considerations alone are not compatible with the constraints imposed by the crystal structure. The resulting strain in the bond lengths can be relaxed inter alia by charge transfer between the two Cu atoms. The effect of the strain and its relaxation is examined using bond valences to model the structure at various compositions. At x = 7.0 the structure adapts by transferring charge between the two crystallographically distinct Cu atoms to give each an oxidation state of about 2.3. At x = 6.0 this mechanism is less effective and the structure contains residual internal strains (BaO bonds stretched and CuO bonds compressed). Between these limits the charge distribution is determined by crystallographic restrictions on the bond lengths. The predictions of the model agree with two recent systematic studies of the structure and are used to show that the 60 K plateau in Tc results from the ordering that occurs at x = 6.5 and that the 90 K plateau is associated with the saturation of Tc as a function of hole concentration. © 1991.
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页码:155 / 167
页数:13
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共 11 条
  • [2] BOND-VALENCE PARAMETERS OBTAINED FROM A SYSTEMATIC ANALYSIS OF THE INORGANIC CRYSTAL-STRUCTURE DATABASE
    BROWN, ID
    ALTERMATT, D
    [J]. ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE, 1985, 41 (AUG): : 244 - 247
  • [4] STRUCTURAL ANOMALIES, OXYGEN ORDERING AND SUPERCONDUCTIVITY IN OXYGEN DEFICIENT BA2YCU3OX
    CAVA, RJ
    HEWAT, AW
    HEWAT, EA
    BATLOGG, B
    MAREZIO, M
    RABE, KM
    KRAJEWSKI, JJ
    PECK, WF
    RUPP, LW
    [J]. PHYSICA C, 1990, 165 (5-6): : 419 - 433
  • [5] CHU CW, 1988, PHYS REV B, V37, P293
  • [6] STRUCTURAL-PROPERTIES OF OXYGEN-DEFICIENT YBA2CU3O7-DELTA
    JORGENSEN, JD
    VEAL, BW
    PAULIKAS, AP
    NOWICKI, LJ
    CRABTREE, GW
    CLAUS, H
    KWOK, WK
    [J]. PHYSICAL REVIEW B, 1990, 41 (04): : 1863 - 1877
  • [7] JORGENSEN JD, 1990, IN PRESS
  • [8] CRYSTAL-CHEMISTRY OF BA2YCU3O7 AND RELATED-COMPOUNDS
    OKEEFFE, M
    HANSEN, S
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1988, 110 (05) : 1506 - 1510
  • [9] PRESSURE-DEPENDENCE OF THE SUPERCONDUCTING TRANSITION-TEMPERATURE IN THE 94-K SUPERCONDUCTOR YBA2CU3O7
    SCHIRBER, JE
    GINLEY, DS
    VENTURINI, EL
    MOROSIN, B
    [J]. PHYSICAL REVIEW B, 1987, 35 (16): : 8709 - 8710
  • [10] THE RELATIONSHIP BETWEEN BOND-VALENCE SUMS AND TC IN CUPRATE SUPERCONDUCTORS
    TALLON, JL
    [J]. PHYSICA C, 1990, 168 (1-2): : 85 - 90