Superconducting Properties of Calcium Substitution in Barium Site of Porous YBa2Cu3O7 Ceramics

2012 ◽  
Vol 501 ◽  
pp. 294-298 ◽  
Author(s):  
A.W. Norazidah ◽  
H. Azhan ◽  
K. Azman ◽  
H.N. Hidayah ◽  
J.S. Hawa
Keyword(s):  
Critical Current ◽  
Solid State Reaction Method ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Metallic Behavior ◽  
X Ray ◽  
Structure Morphology ◽  
Small Change ◽  
Critical Current Density Jc ◽  
Barium Site

The influence of calcium substitution at the barium site of porous Y(Ba1-xCax)2Cu3Oδ (x= 0.00, 0.10, 0.20 and 0.30) samples prepared via solid-state reaction method have been investigated. The structure, morphology, critical temperature and critical current were determined by x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and four-point probe method, respectively. Generally, the curves of normalized resistance for all samples displayed normal metallic behavior above Tc onset. The Tc zero was between 84 K and 71 K with increase in Ca concentration corresponding to a small change of carrier concentration. The critical current density, Jc decreases with increase in Ca concentration. The highest Jc of 2.657 A/cm2 at 50 K was obtained in Ca-free porous YBCO which is higher than that of Ca-free non porous YBCO. Further substitution of Ca at Ba site decreased Jc monotonously. The increase of Ca concentration decreased the volume of unit cell but the crystallographic structure remains in the orthorhombic form where a≠b≠c. The grains are highly compacted and randomly distributed while the grain size decreased as the Ca concentration increased.

The Effects of Nanoparticle Addition in Bi-2212 Superconductors

2014 ◽  
Vol 69 (2) ◽  
Author(s):  
M. A. Suazlina ◽  
S. Y. S. Yusainee ◽  
H. Azhan ◽  
R. Abd-Shukor ◽  
R. M. Mustaqim
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Density Measurement ◽  
Solid State Reaction Method ◽  
Crystallographic Structure ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
Oxide Powders ◽  
Critical Current Density Jc

The effect of Y2O3 nanoparticle addition on the superconducting properties of Bi1.6Pb0.4Sr 2CaCu 2Oy have been investigated. The samples were prepared using high purity oxide powders via solid state reaction method. Y2O3 nanoparticle with 0.0-1.0 wt. % was systematically added to the well balanced Bi1.6Pb0.4 Sr2CaCu2Oy before sinter in order to trace the existense of nanoparticle addition in the system. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and critical current density, Jc. The current density measurement was done via four-point probe method under zero magnetic fields. The critical current density, Jc and superconductivity transition temperature, Tc for sample with addition of Y2O3 nanoparticle were found to be higher than the pure sample. The optimal addition of Y2O3 nanoparticle to the sample Bi-2212 system was found at 0.7 wt. %. The crystallographic structure of all samples was evidenced to be orthorhombic where a ≠ b ≠ c. Changes in superconducting properties of Y2O3 nanoparticle added Bi-2212 system were discussed.

Effect of Ni0.5Zn0.5Fe2O4 Nanoparticles Addition on Tl-1212 High Temperature Superconductor

2020 ◽  
Vol 307 ◽  
pp. 98-103
Author(s):  
Wei Kong ◽  
Christopher Jacob ◽  
Ing Kong ◽  
Cin Kong ◽  
Eng Hwa Yap ◽  
...  
Keyword(s):  
Critical Current ◽  
High Temperature Superconductor ◽  
Diffraction Method ◽  
Solid State Reaction Method ◽  
Transport Critical Current Density ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Powders ◽  
A Value ◽  
Average Size

The effects of Ni0.5Zn0.5Fe2O4 nanoparticle addition on the superconducting and transport properties of (Tl0.85Cr0.15)Sr2CaCu2O7 (Tl-1212) superconductor were investigated in this paper. The Tl-1212 samples were produced by mixing high purity oxide powders through a solid-state reaction method. Nano Ni0.5Zn0.5Fe2O4 particles with compositions of 0.001 wt.%, 0.003 wt.%, 0.005 wt.%, 0.01 wt.% and 0.02wt.% with average size of 60 nm were added into the Tl-1212 powders. The transition temperatures (Tc-zero and Tc-onset) were measured using a four-point probe method. The highest Tc-zero recorded was 97 K which was exhibited by the pure Tl-1212 sample. The transport critical current, Ic, of the Tl-1212 samples were found through the 1 µV/cm criterion with temperature ranging from 30 K to 77 K. The sample with a composition of 0.003 wt.% displayed the highest value of Jc at 77 K with a value ranging up to 1780 mA/cm2. The Tl-1212 samples were characterised using scanning electron microscopy (SEM), powder X-ray diffraction method (XRD), energy dispersive X-Ray analysis (EDX), electrical resistance measurements and transport critical current density measurements. The Jc of the Tl-1212 superconductor has been improved through the addition of Ni0.5Zn0.5Fe2O4 nanoparticles but adding an excessive amount has caused its Jc to degrade.

Synthesis and Characterization of Low Density Bi-2223 Cuprates Superconductor Doped Eu2O3 Nanoparticles

2021 ◽  
Vol 317 ◽  
pp. 131-137
Author(s):  
Suhaimi Nurbaisyatul Ermiza ◽  
Azhan Hashim ◽  
Azman Kasim ◽  
Norazila Ibrahim ◽  
Siti Fatimah Saipuddin
Keyword(s):  
Solid State Reaction Method ◽  
Synthesis And Characterization ◽  
Crystallographic Structure ◽  
Low Density ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Resistivity Measurements

Bi1.6Pb0.4Sr2Ca2-xEuxCu3Oδ cuprates superconductor doped with Eu nanoparticles (x = 0.0000, 0.0025, 0.0200 and 0.0500) were synthesized through conventional solid state reaction method. Crystalline sucrose was added during pelletization and burn at 400°C for two hours to create low density sample. The effect of doping Eu2O3 nanoparticles on the structural and superconducting properties by means of critical temperature (Tc), critical current density (Jc), X-ray diffraction (XRD) together with Field Emission Scanning Electron Microscopy (FESEM) and Alternating Current Susceptibility (ACS) were studied. Based on XRD analyses, the crystallographic structure has shown slightly changed from tetragonal to orthorhombic. The amount of 2223 phase gradually decreased with the increment of Eu concentration which indicates that Eu nanoparticles substitution favours the growth of 2212 phases. The resistivity measurements show that the highest Tcvalue for doped samples found at 90 K for x = 0.0025. The FESEM images showed that the plate-like grains become smaller and distributed randomly without specific alignment due to the increment of Eu concentration.

PREPARATION AND CHARACTERIZATION OF CIS POWDERS BY A FACILE REFLUXING REACTION ROUTE

2013 ◽  
Vol 12 (05) ◽  
pp. 1350031
Author(s):  
J. C. ZHOU ◽  
Y. Y. WANG ◽  
X. L. GONG ◽  
S. W. LI
Keyword(s):  
Single Phase ◽  
Stoichiometric Composition ◽  
Chalcopyrite Structure ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
X Ray ◽  
Structure Morphology ◽  
Short Time

CuInSe 2 (CIS)-based powders were successfully prepared by a facile refluxing reaction route using metal halides and Se / S powder as raw starting materials. The phase and crystallographic structure, morphology, chemical composition of the products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS). It is found that single phase CIS powders with chalcopyrite structure can be prepared in a relatively short time using triethylenetetramine as the solvent; the most suitable reaction temperature and time are 200°C, 1–2 h, respectively. CuIn ( S x Se 1-x)2 powders were also prepared by refluxing reaction route using the mixed solvent of triethylenetetramine–glycol (1:1, v/v). The characterizations showed that the CuIn ( S x Se 1-x)2 has single chalcopyrite phase, and the stoichiometric composition closely follows the primary mixed ratio. The morphology of CuIn ( S x Se 1-x)2 is close to spheres, and the particle sizes become distinctly smaller with the incorporation of S . A possible formation mechanism of CuInSe 2 was put forward and briefly discussed.

A Modified Hydrothermal Synthesis and Luminescence of Hydroxyapatite Doped with Ce3+ and Tb3+ Ions

2013 ◽  
Vol 750-752 ◽  
pp. 1639-1642
Author(s):  
Si Hua Wang ◽  
Zhi Gang Liu ◽  
Qiao Wang ◽  
Li Rong Yang ◽  
Feng Feng Li ◽  
...  
Keyword(s):  
Lattice Structure ◽  
Hydrothermal Process ◽  
Hexagonal Lattice ◽  
Luminescent Properties ◽  
Emission Lines ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dispersed Particles ◽  
Structure Morphology ◽  
Small Change

Luminescent Ln3+ (Ce3+, Tb3+) doped hydroxyapatite (HAp: Ce, Tb) phosphors were successfully fabricated via the modified hydrothermal process. The structure, morphology, and luminescent properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) spectra respectively. The XRD results reveal that the obtained HAp: Ce, Tb phosphors show the characteristic peaks of hydroxyapatite in a hexagonal lattice structure and the import of Ce3+and Tb3+ causes small change in the crystalline structure and leads to the peaks shifting and declining. It is observed that the as-prepared luminescent samples exhibit nearly equiaxial morphology of dispersed particles about 50-150 nm in size. Under 254 nm UV radiation excitation, the phosphors demonstrate the characteristic 5D47F36 emission lines of Tb3+and the excitation of Tb3+ is mainly caused by the energy transfer from Ce3+. PL intensity of Tb3+ doped HAp remarkably strengthened with increment of Ce3+ concentration and reached the maximum at the concentration of 4 mol%.

scholarly journals Superconducting Properties of Bi2-xPb0.3WxSr2Ca2Cu3O10+ Compounds

2021 ◽  
pp. 490-495
Author(s):  
Mohammed J. Tuama ◽  
Lamia K. Abbas
Keyword(s):  
Volume Fraction ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Crystallographic Structure ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Two Phases ◽  
Parameter Values

The conventional solid-state reaction method was utilized to prepare a series of superconducting samples of the nominal composition Bi2-xPb0.3WxSr2Ca2Cu3O10+d with 0≤x≤0.5 of 50 nm particle size of tungsten sintered at 8500C for 140h in air . The influence of substitution with W NPs at bismuth (Bi) sites was characterized by the X-ray diffraction (XRD), scanning electron microscopy (SEM) and dc electrical resistivity. Room temperature X-ray diffraction analysis revealed that there exists two phases, i.e. Bi-(2223) and Bi-(2212), in addition to the impurity phases of (SrCa) 2Cu2O3, Sr2Ca2Cu7Oδ, Ca2PbO4, CaO, and WO. It was found that the crystallographic structure of all samples was orthorhombic. Lattice parameter values and the volume fraction of the (2223)-phase of the prepared samples were also calculated. The superconductivity transition temperature (Tc) for samples subjected to substitution with W NPs was found to be higher than that for the pure sample. The optimal value of W NPs content in (Bi, Pb)-2223 system was found to be at x=0.3. 

Evidence of Hole Self-Doping due to Excess Oxygen Addition in Polycrystal LaMnO3

2021 ◽  
Vol 1023 ◽  
pp. 9-13
Author(s):  
Hiromi Kobori ◽  
Megumi Sogabe ◽  
Akinori Hoshino ◽  
Atsushi Yamasaki ◽  
Toshifumi Taniguchi ◽  
...  
Keyword(s):  
Solid State Reaction Method ◽  
Molar Ratio ◽  
Excess Oxygen ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Metallic Behavior ◽  
Gas Atmosphere ◽  
Electrical Resistivities ◽  
Oxygen Gas ◽  
Oxygen Addition

We have presented the evidence of hole self-doping due to excess oxygen addition in polycrystal LaMnO3 (LMO). The polycrystal LMO samples were prepared by use of a solid-state reaction method. Powder mixtures with a molar ratio of 1:1 between La2O3 and Mn2O3 were pre-annealed at 1100oC for 18 hours in the atmospheres of oxygen gas, helium gas and vacuum. By this heat treatment, non-crystalline LMO samples were produced. After that, the non-crystalline LMO samples were grinded and were pressed into pellets at the pressure of 3t/cm3. The pellets were annealed at 1100oC and 1300oC for 18 hours in the same atmospheres as the pre-annealing. Through these processes, polycrystal LMO samples were finally produced. To investigate crystallographic structure of the LMO samples, X-ray diffraction (XRD) measurements were performed by use of Cu-K radiation. From the experimental results of XRD measurements, we have found that all LMO samples have perovskite structure and are polycrystals. In addition, to investigate surface structure of the LMO samples, scanning electron microscope (SEM) measurements were carried out. Electrical resistivities (ERs) of the polycrystal LMO samples were measured as a function of temperature (4K-300K). The ERs of polycrystal LMO samples produced in an oxygen gas atmosphere show lower values as compared with other LMO ones in He gas and vacuum atmospheres. Especially, the temperature dependence of the ER for a polycrystal LMO sample produced at the annealing temperature of 1100oC in an oxygen atmosphere shows a metallic behavior. Thus, we have considered that this LMO sample has the largest hole self-doping concentration in all LMO ones.

Impact of Eu Nanoparticles Substitution for Ca Site in Bi(Pb)-2223 Cuprates Superconductor

2020 ◽  
Vol 301 ◽  
pp. 202-208
Author(s):  
E.S. Nurbaisyatul ◽  
H. Azhan ◽  
Kasim Azman ◽  
Norazila Ibrahim ◽  
Siti Fatimah Saipuddin
Keyword(s):  
Critical Temperature ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Solid State Reaction Method ◽  
Nominal Composition ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
Effective Surface ◽  
X Ray

The sample with nominal composition of Bi1.6Pb0.4Sr2Ca2-xEuxCu3Oy where x = 0.000, 0.0025, 0.020, 0.050 and 0.100 were synthesized through solid state reaction method. The effect of Eu2O3 nanoparticles doping on the superconducting and structural properties were studied by means of critical temperature, TC, critical current density, JC, X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The amount of 2223 phase gradually decreased with the increment of Eu concentration which indicates that Eu nanoparticles substitution at Ca site favours the growth of 2212 phases. The sample with higher porosity was found to be decreased in critical temperature, TC as well as critical current density, JC due to the lack of effective surface area for current flowing. The best superconducting properties were observed at x = 0.0025 substitutes into Ca site for Bi (Pb)-2223 host sample.

Effect of Yb Substitution in Bi1.6Pb0.4Sr2Ca2-xYbxCu3Oy Superconductor

2013 ◽  
Vol 667 ◽  
pp. 43-47
Author(s):  
J.S. Hawa ◽  
H. Azhan ◽  
S.Y.S. Yahya ◽  
K. Azman ◽  
H.N. Hidayah ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Resistivity Measurement ◽  
Lattice Parameter ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Pure Sample ◽  
X Ray ◽  
Ionic Size ◽  
Small Change ◽  
Scanning Electron

This paper reports on the results of Yb substitution for Ca on the superconductivity and structural properties of Bi1.6Pb0.4Sr2Ca2-xYbxCu3Oy superconducting samples with x = 0.000, 0.025, 0.050, 0.100 and 0.200 which prepared by coprecipitation (COP) method. The samples were characterized by X-ray diffraction (XRD), field-emission scanning electron (FESEM), electrical and resistivity measurement by four-probe method. It was found that the substitution of Yb decreased the critical temperature (Tc zero), critical current density (Jc) and volume fraction of Bi-2223 phase. The samples have Tc zero in the range 77 to 100 K. Tc zero gradually decreased with an increase in Yb concentration, corresponding to small change of the carrier concentration. Jc was measured to be 5.7512 A/cm2 for pure sample and decreased to 4.1910 A/cm2 for x = 0.025 at 77 K. The crystallographic structure was found to change slightly from tetragonal to orthorhombic in Yb substituted samples. The lattice parameter c of Yb samples decreased due to the incorporation of Yb3+ (0.858 Å) with smaller ionic size compare to Ca2+ (0.99 Å). From the SEM observation, the grain connectivity became weak with smaller plate-like grain for x > 0.025 Yb concentration resulting in the decreased of Jc.

Electrical and Structural Properties of Ca Substitution in High and Low Density Y(Ba1-xCax)2Cu3O7-δ Superconductor

2016 ◽  
Vol 846 ◽  
pp. 586-590
Author(s):  
Azhan Hashim ◽  
Abd Wahab Norazidah ◽  
Azman Kasim ◽  
A. Nazree ◽  
S. Akmal Syamsyir ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Structural Properties ◽  
Structural Identification ◽  
Solid State Reaction Method ◽  
High Density ◽  
Crystallographic Structure ◽  
Low Density ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ca Substitution

The effect of Ca substitution on the electrical and structural properties in high and low density Y(Ba1-xCax)2Cu3Oδ where x = 0.00, 0.10, 0.20 and 0.30 via solid state reaction method has been investigated. The electrical properties, elemental analysis, and structural identification were measured by the four-point probe technique, energy dispersive x-ray (EDX) and X-ray diffraction (XRD) respectively. The electrical properties such as critical temperature (Tc) and critical current density (Jc) were found to be strongly dependent in both high and low densities Y(Ba1-xCax)2Cu3O7-δ. These parameters were decreased monotonously with the increasing of Ca substitution. An obvious results of the Ca-doped samples can be seen in x = 0.20 where Tc zero of high density sample is 77 K, which is higher than that of the low density sample that occurred at 73 K. Meanwhile, Jc at 60 K for high density is 1.842 A/cm2 compared to 1.410 A/cm2 in low density sample. EDX analysis confirmed the existence of Ca in all doped samples. The crystallographic structure remained orthorhombic and the volume of unit cell increased towards further increased of Ca concentration.

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