Effects of morphology of Mg powder precursor on phase formation and superconducting properties of Mg11B2 low activation superconductor

2018 ◽  
Vol 6 (30) ◽  
pp. 8069-8075 ◽  
Author(s):  
Feng Cheng ◽  
Zongqing Ma ◽  
Liming Yu ◽  
Chong Li ◽  
Chenxi Liu ◽  
...  
Keyword(s):  
Phase Formation ◽  
Sintering Process ◽  
Superconducting Properties ◽  
Powder Precursor

The sintering process of Mg11B2 sample using spherical Mg powder is different from the plate-like one (usual used).

Dielectric properties of (SWCNTs)x GdBa2CuO7−δ superconductor nanocomposites

2017 ◽  
Vol 31 (31) ◽  
pp. 1750290 ◽  
Author(s):  
M. Anas ◽  
S. Ebrahim ◽  
I. G. Eldeen ◽  
R. Awad ◽  
A. I. Abou-Aly
Keyword(s):  
Dielectric Properties ◽  
Phase Formation ◽  
Dielectric Response ◽  
Single Walled Carbon Nanotubes ◽  
Superconducting Phase ◽  
Sintering Process ◽  
Superconducting Properties ◽  
Solid State Reaction Technique ◽  
Micro Cracks ◽  
Walled Carbon Nanotubes

Gd-123 superconducting phase was prepared by solid-state reaction technique. Single-walled carbon nanotubes (SWCNTs) were added in Gd-123 superconducting matrix with different concentrations during the final sintering process to obtain (SWCNTs)[Formula: see text] GdBa2Cu3O[Formula: see text] (x = 0.0–0.1 wt.%) nanoparticles–superconductor composite. The influence of SWCNTs addition on the phase formation, structural, morphological, superconducting and dielectric properties of Gd-123 phase was investigated. It was found that SWCNTs addition enhance the phase formation and does not change the crystal structure of the host Gd-123 superconducting phase. The superconducting properties of Gd-123 samples were improved after the addition of SWCNTs up to x = 0.06 wt.% due to the enhancement in intergrain connectivity by healing up of micro-cracks and reduction of defects, while these properties were retarded with further increase in x. The dielectric response of (SWCNTs)[Formula: see text] Gd-123 superconducting phase with x = 0.0, 0.01, 0.04, 0.05, 0.06 and 0.1 wt.% was measured from 100 KHz to 5 MHz at 77 K. The results reveal that for both real ([Formula: see text]) and imaginary ([Formula: see text]) parts of dielectric constant, the frequency of dispersion increased by increasing SWCNTs amount up to 0.06 wt.%, then this frequency shifted to lower values for x [Formula: see text] 0.06 wt.%. The results were discussed according to the presence and interference of both interfacial and dipolar polarizations.

Microstructure and superconducting properties of Bi-2223/Ag tapes fabricated in the pressing–melting–sintering process

2010 ◽  
Vol 470 (20) ◽  
pp. 1388-1391 ◽  
Author(s):  
X.Y. Lu ◽  
D. Yi ◽  
H. Chen ◽  
A. Nagata ◽  
K. Sugawara
Keyword(s):  
Sintering Process ◽  
Superconducting Properties

Effect of WC Addition on Phase Formation and Microstructure of TiC-Ni Composites

2008 ◽  
Vol 55-57 ◽  
pp. 353-356
Author(s):  
Nawarat Wora-uaychai ◽  
Nuchthana Poolthong ◽  
Ruangdaj Tongsri
Keyword(s):  
Liquid Phase ◽  
Tungsten Carbide ◽  
Phase Formation ◽  
Liquid Phase Sintering ◽  
Precipitation Process ◽  
Solid Solution Phase ◽  
Binder Phase ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray

In this research, titanium carbide-nickel (TiC-Ni) composites, with tungsten carbide addition, were fabricated by using a powder metallurgy technique. The TiC-Ni mixtures containing between 0-15 wt. % tungsten carbide (WC), were compacted and then sintered at 1300°C and 1400°C, respectively. The phase formation and microstructure of the WC-added TiC-Ni composites have been investigated by X-ray diffraction and scanning electron microscopy techniques. Mechanical properties of these composites were assessed by an indentation technique. The X-ray diffraction patterns showed no evidence of tungsten rich phases in the sintered WC-added cermets. This indicates that during the sintering process, tungsten carbide particles were dissolved in metallic binder phase (Ni phase) via dissolution/re-precipitation process during liquid phase sintering. The liquid phase formed during sintering process could improve sinterability of TiC-based cermets i.e., it could lower sintering temperatures. The TiC-Ni composites typically exhibited a core-rim structure. The cores consisted of undissolved TiC particles enveloped by rims of (Ti, W)C solid solution phase. Hardness of TiC-Ni composites increased with WC content. Sintering temperature also had a slight effect on hardness values.

Effect of V Additions on Bi2223 Phase Formation and Superconducting Properties of (Bi,Pb)2Sr2Ca2Cu3Oz

1998 ◽  
pp. 561-567
Author(s):  
H. Maeda ◽  
K. Kakimoto ◽  
M. Kikuchi ◽  
J. O. Willis ◽  
K. Watanabe ◽  
...  
Keyword(s):  
Phase Formation ◽  
Superconducting Properties

Sintering of Textured YBa2Cu307-x Under Intensive 60Co Gamma Irradiation

1994 ◽  
Vol 354 ◽  
Author(s):  
Elvira M. Ibragimova ◽  
Eldar M. Gasanov ◽  
Makhmud Kalanov ◽  
Marquis A. Kirk ◽  
Ken C. Goretta
Keyword(s):  
Gamma Irradiation ◽  
Dose Rate ◽  
Subsurface Layer ◽  
Gamma Dose ◽  
Ordered Structure ◽  
Sintering Process ◽  
Superconducting Properties ◽  
Oxygen Sublattice ◽  
60Co Gamma ◽  
Sem Analyses

AbstractA study of structural and superconducting characteristics of YBa2Cu307-x ceramics sintered after and in the course of gamma-irradiation is reported. Using X-difraction and SEM analyses and transport measurements, it has been shown that mainly the subsurface layer of crystallites and intergrain contacts are affected by the irradiation by means of sorption/desorption of oxygen and ordering/disordering in oxygen sublattice, which depends on gamma dose rate and dose. The irradiation provides the sintering process with an additional superthermal energy to form the orthorhombic well-ordered structure and to obtain dense ceramics possessing strong intergrain contacts and improved and stable superconducting properties

The effect of B2O3 impurity in the original B powder on the phase formation of MgB2 during the sintering process

2011 ◽  
Vol 471 (23-24) ◽  
pp. 1660-1663 ◽  
Author(s):  
Ying Tang ◽  
Xiangjie Kong ◽  
LiDe Fang ◽  
Hongtao Wang
Keyword(s):  
Phase Formation ◽  
Sintering Process
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