Time Dependent Changes in Ag Doped YBCO Superconductors

Flux pinning in Al doped TSMG YBCO bulk superconductors

The superconducting properties of Y1Ba2(Cu1−x Alx)3O7/Y2BaCuO5 bulk superconductors with different Al contents were studied (x = 0.0025–0.05). A peak effect was observed at intermediate magnetic fields over a wide temperature range below Tc. The influence of standard oxygenation (SO) at 400 ◦C and high pressure oxygenation (HPO) at 750 ◦C on the critical current density Jc was investigated. We ...

Order Parameter Symmetry in Doped YBCO Systems

Intense experimental and theoretical efforts have recently been brought to bear on the determination of the symmetry of superconducting order parameter in high Tc Cuprates as this would shed light on the nature of microscopic interactions that are responsible for superconductivity in these unusual systems. We use a two band model that reproduces the Fermi surface seen in ARPES experiments of Sh...

Oxygen determination from cell dimensions in YBCO superconductors

A rapid and simple procedure for the determination of non-stoichiometric oxygen in YBa2Cu3O7 d (YBCO) superconductors is described, based on the relationship between oxygen content and c-axis parameter of the YBCO structure. To test the proposed method the oxygen content of samples sinterised starting from different precursors has been calculated from X-ray powder diffraction analysis and compa...

YBCO Blazes the Trail for High-Temperature Superconductors

Anomalous Anharmonicity in Doped Cuprate Superconductors

Strong nonlinear elastic effects arise due to the Lifshitz transition associated with a change in the Fermi surface topology. It is shown that an electronic contribution to the elastic characteristics of cuprates becomes important if the chemical potential is near but not too near the Van Hove critical energy εc. In the case of a saddle point singularity in the energy spectrum an enhancement fa...