Possible highTc superconductivity in the Ba−La−Cu−O system

  title={Possible highTc superconductivity in the Ba−La−Cu−O system},
  author={J. Georg Bednorz and K. Alex M{\"u}ller},
  journal={Zeitschrift f{\"u}r Physik B Condensed Matter},
  • J. Bednorz, K. Müller
  • Published 1 June 1986
  • Materials Science, Physics
  • Zeitschrift für Physik B Condensed Matter
Metallic, oxygen-deficient compounds in the Ba−La−Cu−O system, with the composition BaxLa5−xCu5O5(3−y) have been prepared in polycrystalline form. Samples withx=1 and 0.75,y>0, annealed below 900°C under reducing conditions, consist of three phases, one of them a perovskite-like mixed-valent copper compound. Upon cooling, the samples show a linear decrease in resistivity, then an approximately logarithmic increase, interpreted as a beginning of localization. Finally an abrupt decrease by up to… Expand
Transport and structural properties of the Ho1Ba2Cu3O9−δ superconductor
The compound Ho1Ba2Cu3O9−δ has been found to be a high Tc superconductor. The onset of the superconducting transition is 88 K with zero resistance achieved at 87 K. The x‐ray diffraction spectrum ofExpand
Phase relation and superconductivity in the oxygen nonstoichiometric system, Ba2YCu3Ox
Abstract The superconducting Ba2YCu3Ox system prepared under various annealing conditions has been characterized by differential thermal analysis, thermogravimetry, powder X-ray diffraction andExpand
Photoemission on the highTc superconductors Y−Ba−Cu−O
XPS and UPS photoemission experiments on the highTc superconductors (Tc≈90 K) with nominal composition YBa2Cu3O9-y (y≈2) show the following:a)The density of electronic states at the Fermi energy isExpand
Superconductivity in YBa2(Cu1−xAgx)3O7−δ oxide system
Abstract The oxide YBa2Cu3O7−δ exhibits superconductivity in the liquid nitrogen temperature range. The Cu ion is in a mixed-valent state in this system and is thought to play a very important roleExpand
Suppression of superconductivity in layered Bi4O4S3 by Ag doping
AbstractWe report X-ray diffraction, magnetization and transport measurements for polycrystalline samples of the new layered superconductor Bi4−xAgxO4S3 (0 ≤ x ≤ 0.2). The superconducting transitionExpand
Superconductivity in the series La3Ba3CaxCu6+xOy, 0≤x≤3, an oxygen deficient tetragonal triple perovskite structure
Abstract The system La 3 Ba 3 Ca x Cu 6+ x O y was chosen for a study as a system on high temperature superconductors. The system retains its tetragonal triple layer perovskite structure over theExpand
Superconductivity in the (Yba2Cu3)1−xNaxO7−δ System
The (YBa2Cu3)1−xNaxO7–δ system in the range of x= 0–0.8 was investigated. Experimental data suggest that the sodium doping with x 0.26 does not affect the critical transition temperature Tc, and theExpand
Superconductivity at 95 K in the single-phase YBa2Cu3O9−y system
Abstract We report the evidence of stable and reproducible high-Tc superconductivity at 95 K in the single-phase compound YBa2Cu3O9−y. It is confirmed that the YBa2Cu3O9−y phase is responsible forExpand
Superconductivity in Ba2/3Pt3B2 with the Kagome lattice
Abstract Resistivity, magnetization and low temperature specific heat (down to 0.4 K) of Ba2/3Pt3B2 with the Kagome lattice of the transition metal Pt atoms have been investigated. The magnetizationExpand
Superconductivity in the Hypervalent Compound Ba2Bi(Sb1−xBix)2 with a Square-Honeycomb Lattice
We studied the structural and physical properties of the hypervalent system Ba2Bi(Sb1−xBix)2 (0 ≤ x ≤ 1) with an anisotropic “square–honeycomb” layer. We found that the orthorhombic Ba2BiSb2 (x = 0)Expand


The oxygen defect perovskite BaLa4Cu5O13.4, a metallic conductor
A new oxygen defect perovskite BaLa4Cu5O13.4, characterized by a mixed valence of copper has been isolated; the parameters of the tetragonal cell are closely related to that of the cubic perovskite:aExpand
Preparation of Superconducting BaPb1-xBixO3 Thin Films by RF Sputtering
Superconducting BaPb1-xBixO3 thin films were successfully prepared by RF diode sputtering with a relatively high deposition rate of 50-120 A/min and subsequent heat treatments above 500 °C. TheirExpand
Possibility of insulator to superconductor phase transition
2014 A phase diagram is postulated where the ground-state of a strongly coupled electron-phonon system is a bipolaronic insulator beyond a critical coupling strength. This opens up the possibility ofExpand
Two-Band Superconductivity in Nb-Doped SrTi O 3
Tunneling measurements have been performed on Nb-doped and reduced superconducting SrTi${\mathrm{O}}_{3}$. Beyond a certain carrier concentration, when a second conduction band gets filled, aExpand
Observation of Grain Boundary Josephson Current in BaPb 0.7 Bi 0.3 O 3 Films
The grain boundaries of superconducting BaPb0.7Bi0.3O3 sputtered thin films were found to work as tunnelling barriers and to result in the Josephson effect. The current-voltage characteristics of theExpand
High temperature superconductivity in the LiTiO ternary system
Abstract The first high temperature superconducting oxide compound is reported. The compound is Li 1+x Ti 2−x O 4 and has the face-centered cubic spinel structure, with a o ≊ 8.40 A . The transitionExpand
Phase diagram of the (LaAlO3)1−x (SrTiO3)x solid-solution system, for x ≤ 0.8
Abstract Mixed LaAlO 3 -SrTiO 3 single crystals have been grown by using flame fusion, starting from homogeneously synthesized solid-solution powders. X-ray powder diffraction of the latter show theExpand
Inhomogeneous superconducting transitions in granular Al
Granular Al films have been measured in a microwave cavity at 9.4 GHz together with their dc resistance, R(T). The change in resonant frequency is proportional to the number of superconductingExpand
Electronic- and crystal-structure effects on superconductivity in the BaPb/sub 1-x/Bi/sub x/O/sub 3/ system
Self-consistent, scalar-relativistic, linear-augmented-plane-wave electronic-structure calculations have been carried out for theExpand
Microwave study of granular superconducting Al films
Abstract Microwave absorption and frequency shift measurements in the normal and in the superconducting state are presented for a metallic type AlAl2O3 film. The results are explained by simpleExpand