Observation of superconductivity (T-c=50 K) in a new tetragonal alkaline-earth cuprate Sr0.8Ba1.2CuO3+delta, synthesised at ambient pressure
The ambient-pressure synthesis of a new tetragonal alkaline-earth superconducting cuprate, Sr0.8Ba1.2CuO3+δ, from a cupro-oxycarbonate is reported. Magnetic-susceptibility measurements show the presence of a superconducting transition ∼ 50 K in a post-annealed sample. The crystal structure, refined...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
1996
|
| Summary: | The ambient-pressure synthesis of a new tetragonal alkaline-earth superconducting cuprate, Sr0.8Ba1.2CuO3+δ, from a cupro-oxycarbonate is reported. Magnetic-susceptibility measurements show the presence of a superconducting transition ∼ 50 K in a post-annealed sample. The crystal structure, refined from time-of-flight powder neutron-diffraction data was found to have an oxygen-deficient La2CuO4-type tetragonal T structure (a = 3.8988(3) Å and c = 12.815(3) Å) with oxygen vacancies located within the CuO2 planes. Ordering of these oxygen vacancies is responsible for the observation of a superlattice in both neutron-and electron-diffraction measurements. An interpretation of the electron-diffraction patterns suggests that the superlattice in Sr0.8Ba1.2CuO3+δ and also in the isostructural superconductor Sr2CuO3+δ are of an identical nature. |
|---|