Laser radiation at 1.06 μm from a pulsed Nd:YAG laser was focused onto a multielement YBa2Cu3O7 target in vacuum and the plasma thus generated was studied using time-resolved spectroscopic techniques. Line broadening of the Ba I emission line at 553.5 nm was monitored as a function of time elapsed after the incidence of a laser pulse on the target. Measured line profiles of barium species were ...

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...

Magneto-optical imaging and magnetization measurements were applied to investigate local formation of superconducting phase effected by a random neck synthesis in Y-Ba-Cu-O system. Polished pellets of strongly inhomogeneous ceramic samples show clearly the appearance of superconducting material in the intergrain zones of binary primary particles reacted under different conditions. Susceptibilit...

In this paper, we report on the sharp peak observed in the third harmonic voltage response generated by a bias sinusoidal current applied to several strips patterned in a YBa2Cu3O7−δ thin film and in two La1−xSrxCuO4 thin films, when the temperature is close to the normal-superconductor transition. The lambda-shaped temperature dependence of the third harmonic signal on the current characterist...

The widely held notion that high-temperature superconductivity originates in the cuprate-planes is proven to be faulty. In the cuprates such as YBa2Cu3O7, we argue that the superconductivity resides in the BaO layers. This superconductivity is s-wave, not d-wave, in the bulk. The trio of ruthenate compounds, doped Sr2YRuO6, GdSr2Cu2RuO8, and Gd2−zCezSr2Cu2RuO10 all superconduct in their SrO lay...

Phase-sensitive tests of pairing symmetry have provided strong evidence for predominantly d-wave pairing symmetry in both the holeand electron-doped high-Tc cuprate superconductors. Temperature dependent measurements in YBa2Cu3O7−δ (YBCO) indicate that the d-wave pairing dominates, with little if any imaginary component, at all temperatures from 0.5K through Tc. In this article we review some o...