The effect of submicron-sized Al2O3 particle addition on the crystal structure and superconducting properties of YBa2Cu3O7-δ ceramics was systematically studied. Series of YBa2Cu3O7−δ + x Al2O3 samples (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5,0.6 wt.% ) were prepared using the solid state reaction method. The lattice parameters and the orthorhombicity were decreased slightly with Al2O3 addition. No ch...

Axions, hypothetical particles theorised to solve the strong CP problem, are presently being considered as candidates for cold dark matter constituents. The signal power of resonant-based axion detectors, known haloscopes, is directly proportional their quality factor Q. In this paper, impact use superconductors on performances haloscopes studied by evaluating obtainable particular, surface res...

YBa2Cu3O7-X tapes fabricated from precursor powder, were used to investigate the effect of sintering conditions on the microstructure. The sintering experiments were carried out in oxygen over the temperature range of 915-950ْC. Scanning electron microscopy was used to examine the sintered products. The result indicated a significant increase in densification and grain growth when the tapes were...

For many possible electronic applications as well as fundamental studies it is essential to fabricate epitaxial layered structures of insulators, semiconductors or normal metals together with hightemperature superconductors (HTS). However HTS materials have complex lattice structures and this makes it difficult to grow multilayers with sharp interfaces preserving epitaxiallity through the whole...

A model is developed for photoinduced absorption from localized states observed in femtosecond pump-probe experiments in high-Tc superconductors and other materials. The dynamics of localized carriers are described in terms of phenomenological approach similar to that originaly proposed by Rothwarf and Taylor. Expanding the relaxation rate in powers of the order parameter we have shown that den...

In cuprates superconductors (as polycrystal and single crystal samples) unusual hysteretic temperature behavior of elastic properties is frequently observed. In this work from the uniform point of view detailed analysis this abnormal temperature behavior of elastic properties is given. It is shown that the hysteretic temperature dependencies of elastic properties of YBa2Cu3O7−δ crystal are stro...

A heterostructure comprised of a 2.7 nm 7 unit cell thick layer of the metallic ferromagnet La2/3Ca1/3MnO3 and two 50 nm thick layers of the high-temperature superconductor YBa2Cu3O7 epitaxially grown on 100 SrTiO3 by pulsed-laser deposition was characterized by magnetization measurements and spherical-aberration-corrected high-resolution transmission electron microscopy HRTEM . The saturation ...

Several experiments were carried out to study the origin of the anomalous photovoltaic eff'ect in high-quality YBa2Cu307 thin films. In particular, the issue of whether the signal is induced by thermal gradients was addressed. Using samples with well-characterized orientation and texture, and using low-power cw lasers, it was determined that the signal was proportional to the thermal gradient a...