Bulk superconductivity at 125 K in Tl2Ca2Ba2Cu3Ox
Abstract
Bulk superconductivity is reported in Tl2Ca2Ba2Cu3Ox with a transition to zero resistance at ~=125 K, the highest transition temperature (Tc) yet found. Transmission electron spectroscopy shows that the unit cell is body-centered tetragonal and contains trilayer Cu perovskitelike units separated by bilayer Tl-O units. Tc in this material varies from 118 to 125 K depending on preparation conditions. A high density of perovskitelike bilayer intergrowths are observed in the 118-K material, which we speculate result in the decreased Tc. A second structure containing only bilayer perovskitelike units-Tl2Ca1Ba2Cu2Ox-is a bulk superconductor with Tc ranging from 95 to 108 K.
- Publication:
-
Physical Review Letters
- Pub Date:
- June 1988
- DOI:
- 10.1103/PhysRevLett.60.2539
- Bibcode:
- 1988PhRvL..60.2539P
- Keywords:
-
- Barium Oxides;
- Copper Oxides;
- High Temperature Superconductors;
- Superconductivity;
- Thallium Compounds;
- Calcium;
- Crystal Structure;
- Electron Diffraction;
- Electron Spectroscopy;
- Perovskites;
- Temperature Effects;
- Solid-State Physics;
- 74.70.Vy