Large a-b anisotropy of the expansivity anomaly at Tc in untwinned YBa2Cu3O7-δ
Abstract
The response of the YBa2Cu3O7-δ lattice to superconducting order is studied using an ultrahigh-resolution capacitance dilatometer. The onset of superconductivity is accompanied by highly anisotropic jumps of the expansivities in the a-b plane. This leads to a reduction of the orthorhombic splitting below Tc, which suggests that superconductivity favors a symmetric (b=a) CuO2 plane. Little effect is seen along the c axis. Superconducting fluctuations are for the first time clearly observed in the lattice expansion.
- Publication:
-
Physical Review Letters
- Pub Date:
- September 1991
- DOI:
- 10.1103/PhysRevLett.67.1634
- Bibcode:
- 1991PhRvL..67.1634M
- Keywords:
-
- Copper Oxides;
- Crystal Lattices;
- Crystal Structure;
- High Temperature Superconductors;
- Superconductivity;
- Yttrium Oxides;
- Anisotropy;
- Barium Oxides;
- Critical Temperature;
- Crystal Growth;
- Strain Distribution;
- Thermal Expansion;
- Solid-State Physics;
- 74.30.Ek;
- 65.70.+y;
- 74.70.Vy