Magneto-transport properties of Co 3 O 4 nanoparticles added (Cu 0.5 Tl 0.5 )Ba 2 Ca 2 Cu 3 O 10-δ superconducting phase

2018 ◽  
Vol 537 ◽  
pp. 283-289 ◽  
Author(s):  
M. Mumtaz ◽  
Mirza Hassan Baig ◽  
M. Waqee-ur-Rehman ◽  
M. Nasir Khan
Keyword(s):  
Transport Properties ◽  
Superconducting Phase ◽  
O 10

Abnormal transport properties of Bi-Ⅲ superconducting phase in pressurized bismuth single crystal

2021 ◽  
Author(s):  
Yufeng Zhang ◽  
Jun Gouchi ◽  
Kento Ishigaki ◽  
Shoko Nagasaki ◽  
Zhixiang Shi ◽  
...  
Keyword(s):  
Single Crystal ◽  
Transport Properties ◽  
Superconducting Phase ◽  
Bismuth Single Crystal

Magnetic and transport properties assisted by local distortions in Bi 2 Mn 4 O 10 and Bi 2 Fe 4 O 9 multiferroic compounds

2015 ◽  
Vol 651 ◽  
pp. 405-413 ◽  
Author(s):  
F.E.N. Ramirez ◽  
G.A. Cabrera-Pasca ◽  
J. Mestnik-Filho ◽  
A.W. Carbonari ◽  
J.A. Souza
Keyword(s):  
Transport Properties ◽  
O 10 ◽  
Local Distortions

Magnetic Transport Properties in GdBa2Cu3−x Ru x O7−δ Superconducting Phase

2012 ◽  
Vol 167 (1-2) ◽  
pp. 59-73 ◽  
Author(s):  
A. I. Abou-Aly ◽  
S. A. Mahmoud ◽  
R. Awad ◽  
I. H. Ibrahim ◽  
M. ME. Barakat
Keyword(s):  
Transport Properties ◽  
Superconducting Phase ◽  
Magnetic Transport

Al2O3 additions for isothermal melt processing of Bi2Sr2CaCu2Oy

1996 ◽  
Vol 11 (9) ◽  
pp. 2135-2141 ◽  
Author(s):  
T.G. Holesinger
Keyword(s):  
Transport Properties ◽  
Grain Growth ◽  
Melt Processing ◽  
Superconducting Phase ◽  
Secondary Phases ◽  
Partial Melt ◽  
Processed Material ◽  
Current Leads ◽  
Approximate Composition ◽  
Melt Solidification

It is shown that additions of Al2O3 (1.0 wt. %) can significantly aid in the isothermal melt processing of Bi2Sr2CaCu2Oy (Bi-2212). Al2O3 additions provide a means for grain refinement of phases present in the partial melt. By limiting grain growth in the partial melt, solidification to form Bi-2212 proceeds more efficiently, resulting in fewer secondary phases and improved transport properties. Aluminum does not substitute into the superconducting phase to any appreciable extent and is present in fully processed material as small, secondary grains of approximate composition Sr2−xCaxAlOy or Bi2Sr4−xCaxAl3Oy · Al2O3 additions were applied to the isothermal melt processing of Bi-2212 thick films and current leads.

The effects of variable oxygen partial pressures during Bi-2223 tape processing

1997 ◽  
Vol 12 (11) ◽  
pp. 3046-3054 ◽  
Author(s):  
T. G. Holesinger ◽  
J. F. Bingert ◽  
J. O. Willis ◽  
V. A. Maroni ◽  
A. K. Fischer ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Transport Properties ◽  
Superconducting Phase ◽  
Phase Assemblage ◽  
Secondary Phases ◽  
Partial Pressures ◽  
Current Densities ◽  
Sinter Cycle

The effect of changes in the oxygen partial pressure during the heat treatment of Bi-2223 tapes has been investigated. Distinct differences were observed in the phase assemblages, compositions, and critical current densities. Of particular importance in the correlation of transport properties and microstructure was the redistribution of lead in both the secondary phases and the Bi-2223 matrix. The highest Jc values were associated with tapes that contained Ca2PbO4 as part of the phase assemblage coupled with lower concentrations of lead in the superconducting phase. The high Jc of 30.4 kA/cm2 was obtained in tapes processed at 820 °C where the oxygen partial pressure was increased from 10% O2/Ar to 20% O2/Ar after 25 h of each 50-h sinter cycle. Samples processed only in 10% O2/Ar at 820 °C did not contain Ca2PbO4, had slightly higher concentrations of lead in the superconducting phase, and had significantly lower Jc values.

Spectroscopic Diagnostics of Tokamaks

1988 ◽  
Vol 102 ◽  
pp. 165-174
Author(s):  
C. de Michelis
Keyword(s):  
Transport Properties ◽  
Power Losses ◽  
Spectroscopic Diagnostics ◽  
Important Concern

AbstractImpurities being an important concern in tokamaks, spectroscopy plays a key role in their understanding. Techniques for the evaluation of concentrations, power losses and transport properties are surveyed, and a few developments are outlined.

Structure and Orientation of As Precipitates in LT-MBE Grown GaAs

1991 ◽  
Vol 49 ◽  
pp. 900-901 ◽  
Author(s):  
Alain Claverie ◽  
Zuzanna Liliental-Weber
Keyword(s):  
Transport Properties ◽  
Layer Thickness ◽  
Growth Temperature ◽  
Low Temperatures ◽  
Lattice Parameter ◽  
Crystalline Quality ◽  
Insulating Properties ◽  
Lt Gaas

GaAs layers grown by MBE at low temperatures (in the 200°C range, LT-GaAs) have been reported to have very interesting electronic and transport properties. Previous studies have shown that, before annealing, the crystalline quality of the layers is related to the growth temperature. Lowering the temperature or increasing the layer thickness generally results in some columnar polycrystalline growth. For the best “temperature-thickness” combinations, the layers may be very As rich (up to 1.25%) resulting in an up to 0.15% increase of the lattice parameter, consistent with the excess As. Only after annealing are the technologically important semi-insulating properties of these layers observed. When annealed in As atmosphere at about 600°C a decrease of the lattice parameter to the substrate value is observed. TEM studies show formation of precipitates which are supposed to be As related since the average As concentration remains almost unchanged upon annealing.

Secondary electron imaging of YBa2Cu3O7-x high-Tc superconductors in Scanning Transmission Electron Microscope

1989 ◽  
Vol 47 ◽  
pp. 684-685
Author(s):  
D. R. Liu ◽  
D. B. Williams
Keyword(s):  
Electron Microscope ◽  
Secondary Electron ◽  
Scanning Transmission Electron Microscope ◽  
Superconducting Phase ◽  
Contrast Imaging ◽  
High Tc ◽  
Bright Contrast ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Imaging

The secondary electron imaging technique in a scanning electron microscope (SEM) has been used first by Millman et al. in 1987 to distinguish between the superconducting phase and the non-superconducting phase of the YBa2Cu3O7-x superconductors. They observed that, if the sample was cooled down below the transition temperature Tc and imaged with secondary electrons, some regions in the image would show dark contrast whereas others show bright contrast. In general, the contrast variation of a SEM image is the variation of the secondary electron yield over a specimen, which in turn results from the change of topography and conductivity over the specimen. Nevertheless, Millman et al. were able to demonstrate with their experimental results that the dominant contrast mechanism should be the conductivity variation and that the regions of dark contrast were the superconducting phase whereas the regions of bright contrast were the non-superconducting phase, because the latter was a poor conductor and consequently, the charge building-up resulted in high secondary electron emission. This observation has since aroused much interest amoung the people in electron microscopy and high Tc superconductivity. The present paper is the preliminary report of our attempt to carry out the secondary electron imaging of this material in a scanning transmission electron microscope (STEM) rather than in a SEM. The advantage of performing secondary electron imaging in a TEM is obvious that, in a TEM, the spatial resolution is higher and many more complementary techniques, e.g, diffraction contrast imaging, phase contrast imaging, electron diffraction and various microanalysis techniques, are available.

Sign in / Sign up

Export Citation Format

Share Document