scholarly journals Effect of Sol-Gel Synthesized BiFeO3 Nanoparticle Addition in YBa2Cu3O7–δ (Y123) Superconductor Synthesized by Standard Solid State Reaction Method

2019 ◽  
Vol 290 ◽  
pp. 245-251
Author(s):  
Abdalla Bahboh ◽  
Abdul Halim Shaari ◽  
Hussein Baqiah ◽  
Soo Kien Chen ◽  
Mohd Mustafa Awang Kechik ◽  
...  

The effects of the multiforric BiFO3 nanoparticles addition on the structure and superconducting properties of YBa2Cu3O7–δ (Y123) with different concentrations were systematically investigated using X-ray diffraction (XRD), field emission scanning electron micrograph (FESEM), EDX and four point probe measurement. It was found that the added samples were predominant by Y-123 phase beside small amount of Y-211 and unreacted BiFeO3 secondary phases. Samples with less (wt.%) BFO added YBCO precursor powder preserved the orthorhombic structure similar to the pure YBCO, while samples with higher wt% addition show orthorhombic-to-tetragonal transition tendency. The samples became more porous and their grain size slightly decreased with addition of BiFeO3. The addition of nanoBiFeO3 disturbed the grain growth of Y123, thus resulting in the degradation of superconducting properties of the samples. The superconducting transition temperature (Tc onset) of samples decreased from 92 K for x=0.0 to 44 K for x=10.0 wt. %, which could be attributable to oxygen vacancy disorder.

1989 ◽  
Vol 03 (04) ◽  
pp. 307-311 ◽  
Author(s):  
N. CAO ◽  
J.Q. ZHENG ◽  
X.Y. SHAO ◽  
X.S. CHEN ◽  
W.Y. GUAN

The composition dependence of superconductivity and crystal structure in La ( Ba 1−x Ca x)2 Cu 3 O 7−y system was determined by the resistivity measurements and X-ray diffraction analysis. The superconducting transition temperature is raised with the increase of Ca content till x=0.6, at which the zero resistance temperature of the sample is 81.5 K. In the meanwhile, the crystal structure of the sample changed from tetragonal (x=0) to orthorhombic structure (x=0.2, 0.4, 0.6). With further increase of Ca content, the superconductivity decrease for the sample of x=0.8 with mixed phases including the orthorhombic oxygen-deficient perovskite-like (ODP) structure and no superconducting transition is found at 4.2 K for the sample of x=1 without the ODP structure. A possible explanation of these experimental results is given.


2007 ◽  
Vol 546-549 ◽  
pp. 2007-2010
Author(s):  
Gao Yang Zhao ◽  
Huang Li Zhang ◽  
Ren Zhong Xue ◽  
Yuan Qing Chen ◽  
Li Lei

precursor solution was prepared using barium trifluoroacetae (Ba-TFA) and non-fluorine yttrium (Y) and copper (Cu) organic salts. The precursor solution was modified by benzalacetone (BzAcH), in which the Cu2+ were chelated with BzAcH, which preventing the loss of Cu in the pyrolysis process. Dense YBCO superconducting films with smooth surface, which confirmed by scanning electron microscopy (SEM), were repeatedly obtained through sol-gel process. X-ray diffraction (XRD) 2θ scanning and φ scanning indicated that the as-prepared YBCO films had good c-axis texture. YBCO films with superconducting transition temperature (TC) above 89K were obtained.


2021 ◽  
Vol 317 ◽  
pp. 131-137
Author(s):  
Suhaimi Nurbaisyatul Ermiza ◽  
Azhan Hashim ◽  
Azman Kasim ◽  
Norazila Ibrahim ◽  
Siti Fatimah Saipuddin

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.


2007 ◽  
Vol 546-549 ◽  
pp. 2035-2039 ◽  
Author(s):  
S.C. Yan ◽  
G. Yan ◽  
Ya Feng Lu ◽  
Y. Feng ◽  
Lian Zhou

Bulk samples with the stoichiometry of Mg:B=1:2 and 1:4 were prepared by solid state reaction method. The microstructure and constituent of the samples were investigated by using the scanning electron microscope (SEM) and the x-ray diffraction (XRD). XRD results showed that the MgB2 phase was first formed in all the samples with different stoichiometry of Mg and B, which indicated that the MgB2 was the most thermodynamically stable phase in the Mg-B binary system. For the samples of Mg:B=1:2, the MgB2 single phase was formed very well when these samples were sintered at 650°C~700°C. For the samples with later added Mg reaching to the stoichiometry of Mg:B=1:2, a longer reaction time or higher reaction temperature was required for the formation of the MgB2 single phase. The SEM results showed that the samples with later added Mg had dense microstructures, suggesting that the later addition of Mg could reduce the porosity of the sample. A small increase of the superconducting transition temperature, Tc, in the Mg addition sample resulted from the dense microstructures.


2007 ◽  
Vol 546-549 ◽  
pp. 1989-1992
Author(s):  
Fang Gao Chang ◽  
Kun Fang ◽  
Gui Lin Song

A superconductor-polymer composite of Bi1.8Pb0.4Sr2Ca2Cu3Oy and ethylene propylene rubber (EPR) was prepared by conventional solid-state reaction method. The phase structure of the composite was characterized by using x-ray diffraction technique. The resistivity of composite samples annealed at different temperatures was measured between 40K and 300K. The results indicate that the resistivity of the as-prepared composite increases with increasing EPR content and shows essentially a semiconducting behavior above Tc. For fixed EPR content, the resistivity of composite samples decreases with increasing annealing temperature. The composite begins to show some signs of superconducting transition at an annealing temperature of 700 °C and zero resistance is reached for samples sintered at 800°C. Thermal gravimetric analysis (TGA) on the composite confirmed that 65% of the EPR content still present in the superconducting composite samples. SEM was used to investigate the surface morphology of the composites. Preliminary results show that the mechanical properties of the composite have been much improved compared with its parent superconductor ceramics.


2010 ◽  
Vol 09 (01n02) ◽  
pp. 19-28 ◽  
Author(s):  
M. EBRAHIMIZADEH ABRISHAMI ◽  
S. M. HOSSEINI ◽  
E. ATTARAN KAKHKI ◽  
A. KOMPANY ◽  
M. GHASEMIFARD

Zn 1-x Mn x O (x = 0, 0.02, 0.06, 0.10, 0.15) nanopowders were synthesized by the sol–gel technique calcinated at low temperatures. By decreasing the grain size in ZnO , the solubility of magnetic impurity has been increased and no detectable secondary phases were observed even in the high Mn -doping samples. The phase formation, size and morphology of nanoparticles were investigated using X-ray diffraction and SEM observations. The samples were ferromagnetic and the Curie point was found in the range 150–170 K for Zn0.94Mn0.06O and 135–150 K for Zn0.98Mn0.02O . Optical characterization and the effect of doping were carried out by means of Fourier transform infrared (FTIR) spectroscopy. Kramers–Kronig analysis was employed to evaluate the optical constants of pure ZnO and ZnO:Mn nanopowders.


1987 ◽  
Vol 99 ◽  
Author(s):  
W. J. Heber ◽  
L. R. Pederson ◽  
G. D. Maupin ◽  
E. J. Leblanc

ABSTRACTSamples of YBa2Cu3O7−x were prepared by solid state reaction of Y2O3, BaO2, and CuO powders mixed in stoichiometric proportions. Powders reacted at 900°C-925°C in air were pressed at 35 MPa into rectangular bars and sintered at 950°C in air for six hours. Slow cooling at 50°C/hour promoted complete transformation to the orthorhombic structure. The effects of subsequent oxidation processing on superconducting properties were also investigated. Oxidation anneals at one atmosphere pressure in flowing O2over the temperature range from 300 to 550°C were performed. Results indicate that oxidation at 450°C optimized the superconducting transition temperature at 91K with a 2-degree transition width. Subsequent high-pressure oxidation (2000 psi O2) at 200°C for one week significantly degraded the superconducting characteristics. Results based on i udometric titration, thermogravimetric analysis, and x-ray photoelectron spectroscopy suggest that the copper valency is about 2.3 and oxygen stoi chiometry is 6.94 (x = 0.06) in samples processed to optimize superconducting properties.


2012 ◽  
Vol 535-537 ◽  
pp. 1031-1034
Author(s):  
Yong Xin ◽  
Guo Yun Chen ◽  
Cheng Hong Luo ◽  
Xin Fa Deng ◽  
Ling Yan Hu

Some samples of La2/3(Ca(1-x)Znx)1/3MnO3 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) were prepared by solid-state reaction method at 1623K. The crystal structures of the compounds were studied by X-Ray Diffraction(XRD). All the samples are orthorhombic structure (Pnma), the symmetry has no obvious change with the increase of Zn atom content x. The crystal lattice constants, Mn-O bond length and Mn-O-Mn bond angle varied with the different Zn content, analyzed by the Rietveld method.


2003 ◽  
Vol 17 (13) ◽  
pp. 2539-2544 ◽  
Author(s):  
T. R. Yang ◽  
V. Toma ◽  
O. Furdui ◽  
G. Ilonca

We have investigated the effect of the partial substitution of Sb for Ru in Ru 1 - x Sb x Sr 2( Sm 0.7 Ce 0.3)2 Cu 2 O 10 - δ, (Ru:1222) prepared by conventional solid state reaction method, using X-ray diffraction analysis, electrical resistivity and DC-magnetic susceptibility measurements. Sb doping reduces the conductivity of the system and the onset superconducting transition temperature decreases from 42 K for x = 0 to 21 K for x = 0.06. This maybe due to a distortion of RuO6 octahedral, which is responsible of the increase in hole localization. The corresponding magnetic moment in the investigated samples is about 0.1 μB for Ru. Furthermore we discuss the influence of phase composition on superconducting and magnetic order.


2010 ◽  
Vol 654-656 ◽  
pp. 1840-1843
Author(s):  
Susil K. Putatunda ◽  
Khurpa S. Vijayaragavan ◽  
Gavin Lawes

Superconducting thin films of magnesium diboride (MgB2) has been synthesized on various substrates such as gold, silver, copper and silicon using a novel electroless plating technique. The microstructures and the superconducting properties of these films have been characterized using X-ray diffraction, scanning electron microscopy and temperature dependent magnetometry. X-ray diffraction measurements confirm that the films are crystalline magnesium diboride with some impurity phases. Clear evidence for a superconducting transition in the magnetization measurements was observed.


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