Measurements of the magnetization are used to determine the dependence of the superconducting transition temperature on the oxygen content in the system YBa1.5Sr0.5Cu3Ox. It is shown that the plateau at 60 K depending on Tc(x) for YBa2Cu3Ox is shifted into the temperature region around 40 K for YBa1.5Sr0.5Cu3Ox. The influence of the hydrostatic pressures up to 1 GPa on the critical parameters of the superconducting state in the ceramic samples YBa1.5Sr0.5Cu3Ox with varying oxygen content (x=6.56-6.95) are investigated. The influence of pressure on the superconducting properties depends strongly on the oxygen content. After applying and removing pressure in samples with an oxygen deficit, a relaxation of the superconducting parameters is observed, associated with oxygen ordering in the Cu-O chains. The oxygen ordering effect (dTc/dP)0 grows as x decreases. Near the metal-insulator transition at x=6.56 the oxygen ordering effect (dTc/dP)0≈20K·GPa-1 predominates over the true pressure effect (dTc/dP)i≈2 K·GPa-1. The characteristic relaxation times of Tc under pressure are determined. The nonmonotonic behavior of Mmin with time upon the application and removal of pressure is due to motion of twin boundaries.
|Number of pages||8|
|Journal||Physics of the Solid State|
|State||Published - 1 Jul 1996|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics