Abstract
During systematic studies of the structural phase diagram of YBa2Cu3O6+x (YBCO), a YBCO single crystal of oxygen concentration x=0.62 turned out to have a tetragonal crystal structure. By magneto-optical imaging of the expulsion of an applied magnetic field, it was shown that the sample was bulk superconducting. This makes the sample highly anomalous in two respects: with a stoichiometry of YBa2Cu3O6.62 the sample should have an orthorhombic symmetry, and a tetragonal undoped sample should not be superconducting at all. Our results corroborate previous findings of Topnikov [JETP Lett. 46, 577 (1987)] of a tetragonal superconducting YBCO crystal with x=0.62.
Original language | English |
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Journal | Physical Review B Condensed Matter |
Volume | 67 |
Issue number | 2 |
Pages (from-to) | 024509 |
Number of pages | 5 |
ISSN | 0163-1829 |
DOIs | |
Publication status | Published - 2003 |