Unstable behavior of theYBa2Cu4O8superconductor under pressure
| Autor: | R. K. Nayar, B. V. Kumaraswamy, S. P. Pandey, Bhanu Pratap Singh, A. V. Narlikar |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Superconductivity
chemistry.chemical_classification High-temperature superconductivity Materials science Analytical chemistry Magnetic susceptibility law.invention Tetragonal crystal system chemistry Electrical resistivity and conductivity law Phase (matter) Orthorhombic crystal system Inorganic compound |
| Zdroj: | Physical Review B. 46:3573-3580 |
| ISSN: | 1095-3795 0163-1829 |
| DOI: | 10.1103/physrevb.46.3573 |
| Popis: | The effect of applied pressure on the YBa 2 Cu 4 O 8 (Y 1:2:4) superconductor with a T c of 78 K up to 50 kbar at ambient temperature is studied. It is observed that Y 1:2:4 undergoes a phase transformation resulting in the YBa 2 Cu 3 O 7 (Y 1:2:3) orthorhombic phase with an increased T c of 92 K. However, beyond 20 kbar, the Y 1:2:3 orthorhombic phase is further converted into the Y 1:2:3 tetragonal phase. The results show that when the pressurized specimens were heat treated again in flowing oxygen at 815°C, the Y 1:2:4 phase with increased superconducting volume fraction is present, as evidenced by ac susceptibility measurements. These results are discussed in terms of solid-state reactions and the structural changes taking place at high pressure. |
| Databáze: | OpenAIRE |
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