Abstract
We have observed a correlation between the lattice-constant ratio c/b and the superconducting transition temperature Tc in R-Be-Cu-O superconductors (where R is a rare-earth element). Madelung potentials and the bond length of Cu(1)-O(3) are calculated and correlated with the distribution of Tc over the various RBa2Cu3O7 superconductors. Further consideration of YBa2Cu3Ox with variable x of suitable oxygen content leads to an explanation of the correlation of decreasing c/b ratio with increasing Tc. A Coulomb-type ionic mechanism is therefore suggested so that shortening of the c axis and increased chain length provides (1) a channel of charge-transfer excitation from chain to Cu-O layers and (2) a long-range Coulomb interaction between the two Cu-O layers, both of which result in stronger coupling between the two Cu-O layers and higher Tc.. AE
Original language | English |
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Pages (from-to) | 9408-9411 |
Number of pages | 4 |
Journal | Physical Review B |
Volume | 40 |
Issue number | 13 |
DOIs | |
Publication status | Published - 1989 Jan 1 |
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics