Surface and superconducting properties of cleaved high-temperature superconductors

1990 ◽  
Vol 64 (5) ◽  
pp. 603-606 ◽  
Author(s):  
J. E. Demuth ◽  
B. N. J. Persson ◽  
F. Holtzberg ◽  
C. V. Chandrasekhar
Keyword(s):  
High Temperature ◽  
High Temperature Superconductors ◽  
Superconducting Properties

Structural and Superconducting Properties of RE1 - 2xPrxCaxSr0.8Ba1.2Cu3O7 - δ (RE = Er and Gd) High Tc Superconductors

2003 ◽  
Vol 17 (13) ◽  
pp. 2609-2622 ◽  
Author(s):  
N. Charoenthai ◽  
P. Winotai ◽  
R. Suryanarayanan ◽  
I. M. Tang
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Transition Temperature ◽  
Size Effect ◽  
High Temperature Superconductors ◽  
Superconducting Properties ◽  
High Tc Superconductors ◽  
High Tc ◽  
Oxygen Annealing ◽  
Ion Size

We report here on the structural and superconducting properties of RE 1 - 2x Pr x Ca x Sr 0.8 Ba 1.2 Cu 3 O 7 - δ (RE = Er and Gd, 0 ≤ x ≤ 0.2) high temperature superconductors. The transition temperature (Tc) of these compounds decreases when the Pr and Ca concentrations are increased. At constant Pr and Ca concentrations, the Tc of Er 1 - 2x Pr x Ca x Sr 0.8 Ba 1.2 Cu 3 O 7 - δ superconductor system is higher than that observed for the Gd 1 - 2x Pr x Ca x Sr 0.8 Ba 1.2 Cu 3 O 7 - δ system. For the Gd 0.8 Pr 0.1 Ca 0.1 Sr 0.8 Ba 1.2 Cu 3 O 7 - δ sample, after heating in argon followed by oxygen annealing, the orthorhombicity increases accompanied by 10 K increase in Tc. These results show that though our data indicate an ion-size effect, the Tc suppression rate dTc/dx depends very much on the heat treatment adopted to prepare the samples.

HETEROSTRUCTURAL FLUCTUATIONS IN SUPERCONDUCTORS

1992 ◽  
Vol 06 (01) ◽  
pp. 91-107 ◽  
Author(s):  
V. I. YUKALOV
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
High Temperature Superconductors ◽  
Crystallographic Structure ◽  
Superconducting Properties

Superconductors are considered in which there occur fluctuations of one crystallographic structure inside another. The role of these heterostructural fluctuations on superconducting properties are analysed. The occurrence of these fluctuations explains anomalous saggings of Mössbauer factor at phase transition in high-temperature superconductors.

Superconducting Properties of Te-Substituted (Tl2-xTex) Ba2CaCu2O8-δ

2019 ◽  
Vol 290 ◽  
pp. 239-244 ◽  
Author(s):  
Syahrul Humaidi ◽  
Eddy Marlianto ◽  
S. Marhaposan ◽  
Roslan Abd-Shukor
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Normal State ◽  
Electrical Resistance ◽  
High Temperature Superconductors ◽  
Solid State Reaction Method ◽  
Precursor Powder ◽  
Superconducting Properties ◽  
State Behavior ◽  
Reaction Method

The Tl2-xTexBa2CaCu2O8-δ (Tl-2212) high temperature superconductors with x = 0.0-0.5 have been prepared by the standard solid-state reaction method. The precursor powder were sintered at 900°C for 24 h with several grindings and heating. The powder were then pressed into pellets and heated at 910°C in oxygen flow for 4 min followed by furnace cooling. The electrical resistance versus temperature dependence measurements showed metallic normal state behavior for all samples. Substitution of Te at the Tl-site led to multi-phasic samples. The x = 0.4 sample showed the highestTc zero= 98 K and Tconset= 111K. The Tl-2212 phase increased from 50% for x=0 up to 92% in the x= 0.4 sample.

SINGLE CRYSTAL GROWTH OF HIGH TEMPERATURE SUPERCONDUCTORS AND INVESTIGATION OF THEIR PHYSICAL PROPERTIES

1989 ◽  
Vol 03 (02) ◽  
pp. 289-302 ◽  
Author(s):  
V. A. TATARCHENKO ◽  
G. A. EMEL'CHENKO ◽  
N. V. ABROSIMOV ◽  
V. A. BORODIN ◽  
L. Ya. VINNIKOV ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Optical Properties ◽  
Crystal Growth ◽  
High Temperature ◽  
Thermal Treatment ◽  
Physical Properties ◽  
Single Crystals ◽  
High Temperature Superconductors ◽  
Single Crystal Growth ◽  
Superconducting Properties

Part of the phase diagram of the La 2 O 3- CuO system has been studied and single crystals of La 2 CuO 4, (LaSr) 2 CuO 4 (up to 20 × 8 × 6 mm 3), YBa 2 Cu 3 O 7−δ (up to 8 × 6 × 0.1 mm 3) and HoBa 2 Cu 3 O 7-(up to 3 × 2.5 × 1 mm 3) have been grown by the method of spontaneous crystallisation, using a rotational crucible. It has been established that thermal treatment of "123" single crystals under oxygen pressure to 10 bars improves their superconducting properties. Electrical, magnetic, optical properties, and the real structure of the single crystals produced have been studied.

Solid-state processing and phase development of bulk (MgO)w/BPSCCO high-temperature superconducting composite

1996 ◽  
Vol 11 (1) ◽  
pp. 8-17 ◽  
Author(s):  
Y. S. Yuan ◽  
M. S. Wong ◽  
S. S. Wang
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Grain Orientation ◽  
High Temperature Superconductors ◽  
Processing Method ◽  
Zero Field ◽  
Superconducting Properties ◽  
Phase Development ◽  
Processing Variables ◽  
State Processing

The inherently weak mechanical properties associated with monolithic high-temperature superconductors (HTS) can be improved by introducing properly selected strong ceramic whiskers into the HTS materials. In this research, processing and superconducting properties of monolithic Pb-doped Bi-2223 (BPSCCO) and MgO whisker-reinforced BPSCCO HTS composite materials have been systematically studied. A solid-state processing method is successfully developed to fabricate the (MgO)w/BPSCCO composite. The HTS composite contains a dense and highly pure BPSCCO matrix phase with a preferred grain orientation, which is reinforced by MgO whiskers randomly oriented in the plane perpendicular to the hot-pressing direction. The HTS composite material is shown to exhibit excellent superconducting properties. For example, a transport Jc measured at 77 K in a zero field has been obtained to exceed 5000 A/cm2 in a (MgO)w/BPSCCO composite with 10% MgO whiskers by volume. Relationships among solid-state processing variables, HTS phase development, and superconducting properties of the monolithic BPSCCO and the HTS composite are established in the paper.

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