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.

Mechanical behavior of MgO-whisker reinforced (Bi, Pb)2Sr2Ca2Cu3Oy high-temperature superconducting composite

1996 ◽  
Vol 11 (7) ◽  
pp. 1645-1652 ◽  
Author(s):  
Y. S. Yuan ◽  
M. S. Wong ◽  
S. S. Wang
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Solid State ◽  
Mechanical Behavior ◽  
Elastic Properties ◽  
High Temperature Superconductors ◽  
Processing Method ◽  
Superconducting Properties ◽  
First Time ◽  
State Processing

The inherently weak mechanical properties of bulk monolithic high-temperature superconductors (HTS) have been a concern. Properly selected reinforcements in fiber and whisker forms have been introduced to the HTS ceramics to improve their mechanical properties. In this paper, mechanical behavior of a MgO-whisker reinforced Pb-doped Bi-2223 (BPSCCO) HTS composite fabricated by a solid-state processing method is studied. The (MgO)w/BPSCCO HTS composite has been shown to exhibit excellent superconducting properties. Elastic properties, strengths, and notched fracture toughnesses of both the monolithic BPSCCO and the (MgO)w/BPSCCO HTS composite are investigated. Detailed mechanical properties are reported for the first time for the (MgO)w/BPSCCO HTS composite. Mechanisms of strengthening and toughening in the MgO-whisker-reinforced HTS composite are also discussed.

Effect of Ag-particulate addition on processing, microstructure, and properties of MgO-whisker-reinforced bulk BPSCCO high-Tc superconductor composites

1996 ◽  
Vol 11 (6) ◽  
pp. 1373-1382 ◽  
Author(s):  
Y. S. Yuan ◽  
M. S. Wong ◽  
S. S. Wang
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Hot Pressing ◽  
Ceramic Materials ◽  
Superconducting Properties ◽  
High Tc ◽  
High Tc Superconductor ◽  
Processing Variables ◽  
Mechanical Strengths ◽  
State Processing

In associated papers [Y. S. Yuan, M. S. Wong, and S. S. Wang, J. Mater. Res. 11, 8–17 (1996); J. Mater. Res. (1996, in press)] it has been shown that weak thermo-mechanical properties of a bulk monolithic high-Tc superconductor (HTS) can be improved by introducing strong ceramic whiskers into the HTS ceramic materials. In this paper, we report a further study of incorporating Ag particulates, (Ag)p, in a bulk monolithic BPSCCO and in the MgO-whisker reinforced BPSCCO composite. Effects of the (Ag)p addition on processing, microstructure, and superconducting and mechanical properties of the bulk monolithic BPSCCO and the (MgO)w/BPSCCO composite are investigated. The results indicate that the highly ductile Ag particulates promote densification of the BPSCCO matrix phase in the composite during hot pressing. The microstructure of the HTS composite with the (Ag)p addition is similar to that in the HTS material without the (Ag)p. The (MgO)w/BPSCCO composite with 10% (by weight) Ag particulates has been shown to possess excellent superconducting properties. The (Ag)p addition to both the monolithic BPSCCO and the (MgO)w/BPSCCO is found to increase appreciably their fracture toughnesses, but has little effects on mechanical strengths of the materials. Quantitative relationships have been established among solid-state processing variables, HTS phase developments, microstructures, and superconducting and mechanical properties of the (Ag)p/BPSCCO and the (MgO)w/(Ag)p/BPSCCO HTS composites.

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.

Powder-diffraction data for several solid solutions with the compositions (CaxSr1−x)CuO2 and (CaxSr1−x)2CuO3

1995 ◽  
Vol 10 (4) ◽  
pp. 296-299 ◽  
Author(s):  
S. T. Misture ◽  
C. Park ◽  
R. L. Snyder ◽  
B. Jobst ◽  
B. Seebacher
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Powder Diffraction ◽  
Solid Solutions ◽  
Diffraction Data ◽  
Solid State Reaction ◽  
High Temperature Superconductors ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Diffraction Patterns

Several compositions of the solid solutions (CaxSr1−x)CuO2 and (CaxSr1−x)2CuO3, both of which are found as minor phases in the high-temperature superconductors, were prepared by solid-state reaction. X-ray powder-diffraction patterns for three compositions of (CaxSr1−x)CuO2 and two for (CaxSr1−x)2CuO3 are presented.

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.

Continuous Two-Dimensional Melting of Vortex-Solid in High Temperature Superconductors

1989 ◽  
Vol 169 ◽  
Author(s):  
N.-C. Yeh
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Defect Density ◽  
High Temperature Superconductors ◽  
Finite Size ◽  
Sample Thickness ◽  
Zero Field ◽  
Two Dimensional ◽  
Thermally Induced ◽  
Transport Studies

AbstractA model of continuous two-dimensional melting in the mixed state of high temperature superconductors is proposed. Two-dimensional melting sets in at a cross-over temperature Tx(H) below the three-dimensinal phase transition Tx(H) due to finite size effects, and Tx(H) is a function of the sample thickness (lc), applied magnetic field (H), and k(= λ/ξ) For a given zero-field transition temperature Tc0 and material properties, (such as defect density), the onset temperature of 2D-melting (Tx(H)) decreases with decreasing sample thickness and increasing magnetic field. In transport studies, thermally induced melting is further complicated by the depinning effect of high current densities.

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.

Sign in / Sign up

Export Citation Format

Share Document