Abstract
Based on the EHMO approach, the energy band structures for superconductors YBa2Cu3−x Sn x O y (y>7) and YBa2Cu3−x Ni x Oy (y<7) were calulated in the present paper. The influence of the cation doping at the Cu site in the unit cell and the oxygen content on their electronic structures was studied. The results showed that the cation doping at the Cu site resulted in the great decreases in the bandwidths of the broad anisotropic Cu-O bands and the densities of states. In YBa2Cu3−x Sn x O y , however, these decreases are compensated by the increase in the oxygen content caused by the Sn-doping, which results in a small change in the total densities of states. For YBa2Cu3−x Ni x O y , the effect of the doping on its electronic structures in dominant. The Ni-doping, therefore, results in a great change in the electronic structures. In addition, the study on the projected densities of states of the Ni-doped system revealed that the 2D Cu-O planes in the Y-Ba-Cu-O system played a dominant role in superconductivity.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Jorgensen JD, Schuttler HB, Hinks DG (1987) Phys Rev Lett 58:1024
Tokura Y, Takadgi H, Uchida S (1989) Nature 337:345
Takadgi H, Uchida S, Tokura Y (1989) Phys Rev Lett 62:1197
Torrance JB et al. (1989) Phys Rev B40:8872
Xiao G, Cieplak MZ, Gavrin A et al. (1988) Phys Rev Lett 60:1446
Beyers R, Shaw TM (1989) Solid State Phys 42:135
Zhang H, Zhao Y, Zhou XY et al. (1990) Phys Rev B42:2253
Zhang H, Zhao Y, Zhou XY et al. (1989) Solid State Commun 71:934
Burdett JK, Kulkarni GV, Levin K (1987) Inorg Chem 26:3650
Kasowski RV, Hsu WY, Herman F (1987) Solid State Commun 63:1077
Kasowski RV, Hsu WY, Herman F (1987) Phys Rev B36:7248
Pickett WE, Krakauer H, Papaconstantopoulos DA et al. (1987) Phys Rev B35:7252
Schwarz K (1987) Solid State Commun 64:421
Papaconstantopoulos DA, Pickett WE et al. (1988) Phys Rev Lett 61:211
Pickett WE (1989) Rev Mod Phys 61:433
Whangbo MH et al. (1978) J Am Chem Soc 100:6093
Whangbo MH et al. (1979) Proc Roy Soc (London) 366A:23
Li Ming (1994) Int J Quantum Chem 50:233
Li Ming, Wu Xiaoping (1994) Theor Chim Acta 89:169
Beno MA, Soderholm L, Capone DW et al. (1987) Appl Phys Lett 51:57
Herman F, Kasowaki RV, Hsu WY (1987) Phys Rev B36:6904
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ming, L., Chuanyue, D. & Wentao, F. Electronic structures of superconductors YBa2Cu3−x M x O y (M=Sn, Ni). Theoret. Chim. Acta 93, 269–279 (1996). https://doi.org/10.1007/BF01127506
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01127506