Two-zone annealing of Tl0.5Pb0.5(Sr0.8Ba0.2)2Ca2Cu3Oy

1994 ◽  
Vol 9 (10) ◽  
pp. 2470-2473 ◽  
Author(s):  
T.L. Aselage ◽  
E.L. Venturini ◽  
J.A. Voigt ◽  
D.L. Lamppa ◽  
S.B. Van Deusen
Keyword(s):  
Single Phase ◽  
Sample Temperature ◽  
Low Field ◽  
Stable Conditions ◽  
Meissner Fraction

Stable conditions have been identified for two-zone processing of the superconducting thallium cuprate Tl0.5Pb0.5(Sr0.8Ba0.2)2Ca2Cu3Oy. With P(O2) of 0.8 atm, P(Tl2O) of 4.4 × 10−3 atm, and a sample temperature of 920 °C, single-phase Tl0.5Pb0.5(Sr0.8Ba0.2)2Ca2Cu3Oy, is produced with a Tc of 115 K, complete diamagnetic shielding, and Meissner fraction greater than 70%. Although a small amount of melting occurs under these conditions, a comparison of the low-field diamagnetic shielding for these samples with samples of Pb- and Sr-free TlBa2Ca2Cu3Oy and Tl2Ba2Ca2Cu3Oy, suggests that such melting is not necessary to produce the triple-CuO2-layer superconductors.

On the low-field Meissner fraction in high-Tc ceramics

1991 ◽  
Vol 169 (1-4) ◽  
pp. 655-656 ◽  
Author(s):  
M. Wetzstein ◽  
R. Behr ◽  
J. Kötzler ◽  
A. Spirgatis ◽  
M. Hartl
Keyword(s):  
High Tc ◽  
Low Field ◽  
Meissner Fraction

Transport and Meissner Effect Studies for YBa2(Cuy1−xZnx)3O7

1987 ◽  
Vol 99 ◽  
Author(s):  
S. H. Bloom ◽  
M. V. Kuric ◽  
Y. S. Yao ◽  
R. P. Guertin ◽  
D. Nichols ◽  
...  
Keyword(s):  
Electrical Resistance ◽  
Single Phase ◽  
High Sensitivity ◽  
Meissner Effect ◽  
Critical Value ◽  
Temperature Dependent ◽  
Metallic Behavior ◽  
Low Field ◽  
Normal Transition ◽  
Support Evidence

ABSTRACTSingle phase orthorhombic YBa2(Cuy1−xZnx)3O7 samples were formed for 0<x<0.16. The high T superconductivityXfor x=6 (T =90 K) is rapidly depressed with increasing x, and is quenched for x>0.08. Low field (<100 G) cooled magnetization studies show that the superconducting component decreases as x approaches the critical value for suppression of superconductivity, and this is supported by high resolution specific heat measurements in the vicinity of T. Temperature dependent electrical resistivity studies for x<0.08 show metallic behavior; for x>0.10 semiconducting behavior. The electrical resistance was studied at high quasihydrostatic pressures also, and for x=0.08 showed that T is depressed with increasing pressure: T → 0 K for P >10 GPa. This is in°contrast to YBa2(Cuy1−xZnx)3O7 where dT /dP>0. The data support evidence for the high sensitivity to chemical and ice perturbations of the physical properties of samples near the superconducting-normal transition region.

Magnetic and 119-Sn Mössbauer Effect Study of Sn-Doped Pb2Sr2Eu.5Cu3-xSnxO8+z (x = 0.0, 0.1) Superconductors

1989 ◽  
Vol 169 ◽  
Author(s):  
P. P. Vaishnava ◽  
C. D. Nelson ◽  
W. P. Pratt
Keyword(s):  
Magnetic Susceptibility ◽  
Mössbauer Effect ◽  
Single Phase ◽  
Effect Study ◽  
Site Symmetry ◽  
X Ray Diffraction ◽  
Mossbauer Effect ◽  
X Ray ◽  
Fraction Increase ◽  
Meissner Fraction

AbstractX-ray diffraction, magnetic susceptibility and 119-Sn Mössbauer effect measurements have been performed on Pb2Sr2Eu.5Cu3-xSnx08+z (x = 0.0, 0.1) superconductors. The x-ray diffraction pattern indicated that the samples are single phase materials. The diamagnetic shielding and the Meissner fraction increase with the introduction of Sn in the lattice. The 119-Sn Mössbauer effect measurements have been used to determine the site symmetry and valence state of Sn atom in the superconductor.

Low-field Meissner fraction of YBaCuO in a flux pinning model

1988 ◽  
Vol 153-155 ◽  
pp. 1469-1470 ◽  
Author(s):  
L. Krusin-Elbaum ◽  
A.P. Malozemoff ◽  
Y. Yeshurun ◽  
D.C. Cronemeyer ◽  
F. Holtzberg
Keyword(s):  
Flux Pinning ◽  
Low Field ◽  
Meissner Fraction

Magnetization studies of the high-Tc compound Y 1Ba2Cu3Oz

1987 ◽  
Vol 2 (6) ◽  
pp. 779-782 ◽  
Author(s):  
J. R. Thompson ◽  
D. K. Christen ◽  
S. T. Sekula ◽  
J. Brynestad ◽  
Y. C. Kim
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Single Phase ◽  
High Tc ◽  
Low Field ◽  
Superconductive State ◽  
Individual Grains

The superconductive state magnetization of the high-Tc compound Y1Ba2Cu3Oz has been investigated. Single-phase, polycrystalline samples of this archetype were prepared by solidstate reaction. The onset of the superconductive transition, measured magnetically, was 90.7 K. In addition to low-field dc magnetization results, measurements of the magnetic critical current density Jc (H,T) are presented as a function of magnetic field and temperature. The low values of Jc, especially at high temperature, are discussed in terms of intergranular supercurrents that flow within individual grains in superconductive layers of reduced dimensionality.

scholarly journals A Single Phase Grid Connected PV System working in Different Modes

2020 ◽  
Vol 10 (5) ◽  
pp. 6374-6379
Author(s):  
P. S. Gotekar ◽  
S. P. Muley ◽  
D. P. Kothari
Keyword(s):  
Single Phase ◽  
Operating Conditions ◽  
Voltage Profile ◽  
Pv System ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Current Controller ◽  
Stable Conditions ◽  
Point Of Common Coupling ◽  
Power Point

The current grid standards for the single-phase residential PV system expect it to operate at Maximum Power Point Tracking (MPPT) mode under normal operating conditions and to maintain the voltage profile whenever a grid fault occurs. The proposed system supplies power to the load under stable conditions and the PV system works in MPPT mode. When the fault occurs at the Point of Common Coupling (PCC) and the voltage is reduced, the proposed controller maintains the voltage profile by injecting the current fed by the current controller at the PCC. The controller shifts from MPPT to the faulty mode and maintains voltage as per grid requirements. During islanding conditions, the PV system successfully caters to the requirements of the load by shifting the control from MPPT to islanding mode. When the PV system is in operation the power quality is enhanced

Anisotrop1C Behavior of a High Tc Superconductor

1987 ◽  
Vol 99 ◽  
Author(s):  
F. A. Otter ◽  
J. I. Budnick ◽  
B. R. Weinberger ◽  
L. Lynds ◽  
D.-P. Yang ◽  
...  
Keyword(s):  
High Field ◽  
Single Phase ◽  
Meissner Effect ◽  
Boundary Effects ◽  
Vibrating Sample Magnetometry ◽  
Single Phase Sample ◽  
High Tc ◽  
High Tc Superconductor ◽  
Low Field ◽  
Trapped Flux

ABSTRACTWe report low and high field vibrating sample magnetometry results and resistance measurements on a highly oriented, single-phase sample of Y1Ba2Cu3O7−x. We find no anisotropy for the low-field (1mT) Meissner effect or trapped flux. Ratios for high field (to 1.9 T) and ρab/ρc are ∼ 2 and 3.6 respectively. Both are different from single-crystal results, a difference we attribute to grain boundary effects.

Influence of Heat Treatments on Microstructures in an Fe-Co-V Alloy

1974 ◽  
Vol 32 ◽  
pp. 512-513
Author(s):  
S. Mahajan ◽  
M. R. Pinnel ◽  
J. E. Bennett
Keyword(s):  
Single Phase ◽  
Alloy Composition ◽  
Supersaturated Solid Solution ◽  
Cell Formation ◽  
Heat Treatments ◽  
Air Cooling ◽  
Iced Brine ◽  
Transmission Electron ◽  
The Matrix ◽  
Bcc Structure

The microstructural changes in an Fe-Co-V alloy (composition by wt.%: 2.97 V, 48.70 Co, 47.34 Fe and balance impurities, such as C, P and Ni) resulting from different heat treatments have been evaluated by optical metallography and transmission electron microscopy. Results indicate that, on air cooling or quenching into iced-brine from the high temperature single phase ϒ (fcc) field, vanadium can be retained in a supersaturated solid solution (α2) which has bcc structure. For the range of cooling rates employed, a portion of the material appears to undergo the γ-α2 transformation massively and the remainder martensitically. Figure 1 shows dislocation topology in a region that may have transformed martensitically. Dislocations are homogeneously distributed throughout the matrix, and there is no evidence for cell formation. The majority of the dislocations project along the projections of <111> vectors onto the (111) plane, implying that they are predominantly of screw character.

Raman And Fluorescence Spectra Observed in Laser Microprobe Measurements of Several Compositions in the Ln-Ba-Cu-O System

1990 ◽  
Vol 48 (2) ◽  
pp. 278-279
Author(s):  
Edgar S. Etz ◽  
Thomas D. Schroeder ◽  
Winnie Wong-Ng
Keyword(s):  
Fluorescence Spectra ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Raman Microprobe ◽  
Methods Of Synthesis ◽  
Compositional Homogeneity ◽  
Processing Techniques

We are investigating by Raman microprobe measurements the superconducting and related phases in the LnBa2Cu3O7-x (for x=0 to 1) system where yttrium has been replaced by several of the lanthanide (Ln = Nd,Sm,Eu,Ho,Er) elements. The aim is to relate the observed optical spectra (Raman and fluorescence) to the compositional and structural properties of these solids as part of comprehensive materials characterization. The results are correlated with the methods of synthesis, the processing techniques of these materials, and their superconducting properties. Of relevance is the substitutional chemistry of these isostructural systems, the differences in the spectra, and their microanalytical usefulness for the detection of impurity phases, and the assessment of compositional homogeneity. The Raman spectra of most of these compounds are well understood from accounts in the literature.The materials examined here are mostly ceramic powders prepared by conventional solid state reaction techniques. The bulk samples are of nominally single-phase composition as determined by x-ray diffraction.

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