Characterizations of YBa5Cu6Ox Superconductor Synthesized by Melt Process

2016 ◽  
Vol 675-676 ◽  
pp. 299-302
Author(s):  
Piyamas Chainok ◽  
Supphadate Sujinnapram ◽  
Thanarat Khuntak ◽  
Tunyanop Nilkamjon ◽  
Sermsuk Ratreng ◽  
...  
Keyword(s):  
Critical Temperature ◽  
Crystal Structures ◽  
Sintering Temperature ◽  
Profile Analysis ◽  
Lattice Parameter ◽  
Resistance Measurement ◽  
Analysis Method ◽  
Full Profile ◽  
Temperature Offset ◽  
Process Method

The YBa5Cu6Ox (Y156) superconductors were synthesized by melt process method with sintering at 980 °C. The samples were characterized by the SEM, EDX, XRD and resistance measurement. The critical temperature onset () and the critical temperature offset () were found at 90 K and 80 K respectively. The crystal structures was orthorhombic performed by Rietveld full-profile analysis method with lattice parameter a = 3.80078 Å, b = 3.89068 Å and c = 22.94436 Å. The c/a ratio was 6.04 and the anisotropy was 2.33. The lower c/a ratio and higher anisotropic were found as increasing the sintering temperature with little change in a and b-axis value. We found that as increasing of sintering temperature, the critical temperature was decreased but the anisotropy was increased.

scholarly journals Some properties of YBamCu1+mOy(m = 2, 3, 4, 5) superconductors

2015 ◽  
Vol 29 (09) ◽  
pp. 1550060 ◽  
Author(s):  
Piyamas Chainok ◽  
Thanarat Khuntak ◽  
Supphadate Sujinnapram ◽  
Somporn Tiyasri ◽  
Wirat Wongphakdee ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Critical Temperature ◽  
Solid State ◽  
Oxygen Content ◽  
Sintering Temperature ◽  
Profile Analysis ◽  
Resistivity Measurement ◽  
Iodometric Titration ◽  
Analysis Method ◽  
Full Profile

We synthesized the YBa m Cu 1+m O y superconductors; m = 2, 3, 4, 5 that were Y123 ( YBa 2 Cu 3 O 7-x), Y134 ( YBa 3 Cu 4 O 9-x), Y145 ( YBa 4 Cu 5 O 11-x), Y156 ( YBa 5 Cu 6 O 13-x), by solid state reaction with the Y 2 O 3, BaCO 3 and CuO as the beginning materials. The calcination temperature was 950°C and varied the sintering temperature to be 950°C and 980°C. The resistivity measurement by four-point-probe technique showed that the Tconset of Y123, Y134, Y145, Y156 were at 97, 93, 91, 85 K, respectively. The XRD and Rietveld full-profile analysis method were used and found that the crystal structure was in the orthorhombic with Pmmm space group with the ratio c/a were 3.0, 4.0, 5.0 and 6.0 for Y123, Y134, Y145 and Y156, respectively. The oxygen content was characterized by Iodometric titration. The ( Cu 3+/ Cu 2+ and Oxygen content) were (0.28, 6.83), (0.19, 8.81), (0.13, 10.79), (0.16, 12.92) of Y123, Y134, Y145, Y156, respectively. We also found that the increasing of sintering temperature has reduced the oxygen content and the critical temperature of all samples.

The Synthesis of YBa3Cu4Ox Superconductor and Comparison with YBa2Cu3Ox

2014 ◽  
Vol 979 ◽  
pp. 220-223
Author(s):  
Piyamas Chainok ◽  
Supphadate Sujinnapram ◽  
Tunyanop Nilkamjon ◽  
Sermsuk Ratreng ◽  
Kiattipong Somsri ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Solid State ◽  
Solid State Reaction ◽  
Profile Analysis ◽  
Analysis Method ◽  
Orthorhombic Structure ◽  
Resistivity Measurements ◽  
Full Profile ◽  
Sem Micrograph

In this research, the Y123 (YBa2Cu3Ox) and Y134 (YBa3Cu4Ox) superconductors were synthesized by solid state reaction and melt process, respectively. The crystal structure of all the samples were then determined using the Rietveld full-profile analysis method to indicate orthorhombic structure. The resistivity measurements showing Tc onset of Y123 lower than Y134 for solid state reaction but higher than Y134 melt process. However, the critical temperature off-set of Y134 has lower than of Y123. The SEM and EDX show that all samples were inhomogeneous. The SEM micrograph for solid state reaction Y123 has many pores between the grain and the grain size clearly demonstrated and bigger than Y134. It was seen that these pores are party eliminated in melt process samples. FTIR spectra detected the trace of carbonate residue in all samples.

Structural and Optical Properties of Zn0.8Co0.2O Ceramics

2008 ◽  
Vol 55-57 ◽  
pp. 337-340
Author(s):  
S. Sujinnapram ◽  
Wandee Onreabroy ◽  
T. Nantawisarakul
Keyword(s):  
Single Phase ◽  
Profile Analysis ◽  
Solid State Reaction Method ◽  
Analysis Method ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Absorption Bands ◽  
Grain Sizes ◽  
Full Profile ◽  
Diffraction Patterns

The Zn0.8Co0.2O ceramics were synthesized by the solid state reaction method with the mixture of ZnO and CoO powders. The mixed powders were sintered at 1200 °C and 1300 °C for 4 hours. It was found that the X-ray diffraction patterns of Zn0.8Co0.2O ceramics were similar to that of the pure ZnO one. The crystal structure of Zn0.8Co0.2O ceramics were then determined using the Rietveld full-profile analysis method to indicate a single phase with a wurtzite-like structure. Their microstructures were examined using the scanning electron microscopy. The results showed that their grain sizes were increased with increasing both the sintering temperatures and the doping effect. Moreover, the optical absorption spectra using UV-Vis spectrometer showed that there were several extra absorption bands appearing in the Zn0.8Co0.2O samples. This confirms that Co2+ is substituted Zn2+ in the wurtzite structure.

Technology of the Contact Wire Manufacture for High-Speed Railways

2021 ◽  
Vol 410 ◽  
pp. 173-178
Author(s):  
Andrey V. Sulitsin ◽  
Raisa K. Mysik ◽  
Vadim V. Morgunov
Keyword(s):  
High Speed ◽  
Profile Analysis ◽  
Cold Drawing ◽  
Casting Process ◽  
Sediment Layer ◽  
Contact Wire ◽  
X Ray ◽  
Inner Surface ◽  
Full Profile ◽  
Continuously Cast

The article presents an overview of possible technological schemes to produce an overhead contact wire for railways. Pilot experiments were carried out on the manufacture of a contact wire made of CuMg0.3, CuMg0.4 and CuMg0.5 alloys and having a nominal cross section of 100 mm2. The contact wire was obtained from a continuously cast rod with small section, which was subjected to plastic deformation using the Conform technology and cold drawing of the extruded rod. In the casting process, we encountered the formation of cracks on the cast rod surface and the rods breakage. The inner surface of the graphite bushings of the mold after casting the rod was studied and a thin gray layer was found on the inner surface of the graphite bushings. Areas of the graphite bushing with gray layer were studied by scanning electron microscopy and element-by-element mapping was performed with the selection of a spectrum in the sediment layer area. In order to determine the phase composition of the sediment layer it was analyzed by the method of full-profile analysis of the X-ray diffraction pattern according to Rietveld. X-ray phase analysis showed the CuMg2 and Cu2Mg phases presence. This allowed us to assume a possible mechanism for the formation of the sediment layer. Ultimate tensile strength, elongation and electrical resistivity was determined. Analysis showed that the overhead wires made of CuMg0.3, CuMg0.4, CuMg0.5 alloys meets the requirements of GOST R 55647-2018 for wires made of the second conditional group bronze.

Combustion Synthesis of Si3N4 from Si/NH4Cl at Low Nitrogen Pressure

2008 ◽  
Vol 368-372 ◽  
pp. 1767-1770 ◽  
Author(s):  
Yi Xiang Chen ◽  
Jiang Tao Li ◽  
Zhi Ming Lin ◽  
Guang Hua Liu ◽  
S.L. Yang ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Combustion Temperature ◽  
Profile Analysis ◽  
Combustion Velocity ◽  
Nitrogen Pressure ◽  
Analysis Method ◽  
Α Phase ◽  
Steady Combustion ◽  
Combustion Wave Velocity ◽  
Low Nitrogen

Combustion synthesis (CS) of Si3N4 was accomplished by using as-milled Si/NH4Cl as reactants at low nitrogen pressure. The additive of NH4Cl decreased the combustion temperature and promoted the Si nitridation. Full nitridation of Si was achieved by burning Si in pressurized nitrogen with 10 ~ 25 wt. % NH4Cl as additives while no Si3N4 diluent added. The maximum combustion temperature (Tc), the combustion velocity (u) together with the α-Si3N4 content and mean particle size (d50) of the powder products were found to be great dependent on the NH4Cl content added in the reactants. Fine Si3N4 powder products with α-phase content up to 85 wt. % were obtained via steady combustion mode. A mathematical approach named combustion wave velocity methods for the analysis of temperature profiles in CS was proposed and the reaction kinetics was discussed. The apparent activation energy calculated according to the temperature profile analysis method is 29.7 kJ/mol, which agrees well with the corresponding low temperature nitriding combustion of Si.

THE EFFECT OF AMOUNT TANTALUM DOPING ON THE PROPERTIES OF MgCuZn FERRITES

2011 ◽  
Vol 25 (19) ◽  
pp. 2583-2591 ◽  
Author(s):  
A. TAWFIK ◽  
M. Z. SAID ◽  
O. M. HEMEDA
Keyword(s):  
Electrical Resistivity ◽  
Sintered Density ◽  
Sintering Temperature ◽  
Lattice Parameter ◽  
Initial Permeability ◽  
Maximum Density ◽  
Preparation Process ◽  
Iron Ions ◽  
Ceramic Method ◽  
Jump Length

The systems MgCuZn Fe 2 O 4 doped (0–0.6 wt% Ta) are prepared by the general ceramic method using the sintering temperature at 1200°C. The variations of the sintered density, lattice parameter, jump length of electrons, and initial permeability were studied. A maximum density was obtained at 1200°C during the preparation process. The electrical resistivity decreases with increasing tantalum ( Ta ) content upto 0.1 wt% and then increases for higher concentrations. The initial permeability and the change carries mobility increase upto 0.1 Ta and then decreases. The jump length decreases with enhancing Ta ions because the substitution of Ta ion with small size instead of Fe 3+ at the A sites increase the concentration of iron ions at the B sites. The increase of the iron content causes the decrease of the jump length of electrons between Fe 3+ and Fe 2+. These improvements of the magnetic properties give some light about the importance of these compositions to be used in technology.

Consolidation and properties of Gd0.1Ce0.9O1.95 nanoparticles for solid-oxide fuel cell electrolytes

2006 ◽  
Vol 21 (1) ◽  
pp. 119-124 ◽  
Author(s):  
A.I.Y. Tok ◽  
L.H. Luo ◽  
F.Y.C. Boey ◽  
J.L. Woodhead
Keyword(s):  
Grain Size ◽  
Ionic Conductivity ◽  
Sintering Temperature ◽  
Spherical Shape ◽  
Impedance Analysis ◽  
Lattice Parameter ◽  
Narrow Particle Size Distribution ◽  
Precipitation Process ◽  
Boundary Area ◽  
Co Precipitation

Gd-doped ceria solid solutions have been recognized to be leading electrolytes for use in intermediate-temperature fuel cells. In this paper, the preparation, solubility, and densification of Gd0.1Ce0.9O1.95 ceramics derived from carbonate co-precipitation are reported. The dissolution of Gd2O3 in CeO2 lattice was identified to be completed during the co-precipitation process by studying the lattice parameter as a function of temperature. After calcination at 800 °C for 2 h, the nano-sized Gd0.1Ce0.9O1.95 powder (∼33 nm) with a nearly spherical shape and a narrow particle-size distribution was obtained. This calcined powder has high sinterability and maximum densification rate at ∼1000 °C. Sintering at 1300 °C for 4 h yielded over 97% relative density with near maximum. The grain size increased with increases in sintering temperature. The ionic conductivity of these pellets was tested by alternating current impedance spectroscopy to elucidate the contribution of intragranular and intergranular conductivity to the total ionic conductivity. It was found that sintering temperature does not affect intragranular conductivity, though intergranular conductivity was strongly influenced by grain size, grain boundary area, and relativity density. This pellet sintered at 1500 °C for 4 h showed a high ionic conductivity of 5.90 × 10−2 s/cm when measured at 750 °C. The characterization and structural evaluation of the as-received powders were carried out using x-ray diffraction, transmission electron microscopy, Brunauer–Emmett–Teller, and dilatometer and impedance analysis.

Surface Profile Analysis for Conformable Interfaces

2003 ◽  
Vol 125 (3) ◽  
pp. 624-627 ◽  
Author(s):  
Mark C. Malburg
Keyword(s):  
Contact Area ◽  
Load Distribution ◽  
Profile Analysis ◽  
Surface Profile ◽  
Solid Surfaces ◽  
Analysis Method ◽  
Uniform Load ◽  
Morphological Filtering ◽  
Novel Method

This paper presents a novel method for the analysis of solid surfaces in contact with a conformable component. These applications are common in many engine and hydraulic applications, wherein conformable seals, gaskets, bushings, etc. are employed to prevent unwanted flow across an interface or provide a uniform load distribution. The proposed analysis method employs a combination of meanline (m-system) filtering and envelope (e-system) or morphological filtering. Through this analysis, a simulation of contact area and the associated voids or gaps can be assessed.

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