scholarly journals Effect of Graphene Nanoparticles Addition on Superconductivity of YBa2Cu3O7~δ Synthesized via the Thermal Treatment Method

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 91
Author(s):  
Aliah Nursyahirah Kamarudin ◽  
Mohd Mustafa Awang Kechik ◽  
Siti Nabilah Abdullah ◽  
Hussein Baqiah ◽  
Soo Kien Chen ◽  
...  

The development of high-temperature superconductor (HTS) YBa2Cu3O7~δ (Y123) bulks in industrial applications were established years ago. It is one of the developments that currently attracts great attention especially in transportation, superconductor cables and wires. This study is focused on the preparation of the Y123 bulk superconductors by the thermal treatment method due to the promising ways to develop high-quality Y123 superconductors with its simplicity, low cost, and relatively low reaction temperature used during the process. Y123 were added with graphene nanoparticles (x = (0.0–1.0) wt.%). Samples were then characterized by X-ray diffraction (XRD) analysis, field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and alternating current susceptibility (ACS). It was found that Y123 confirmed that the majority of phases in all the XRD patterns was the orthorhombic crystal structure and the Pmmm space group with secondary phases belonged to Y2Ba1Cu1O5 (Y211). The highest Tc obtained when graphene nanoparticles were added in the Y123 sample was x = 1.0 wt.%, followed by x = 0.5 wt.% with 92.64 and 92.59 K, respectively. From the microstructure analysis, the average grain size significantly decreased to 4.754 µm at x = 0.5 wt.%. The addition of graphene nanoparticles had disturbed the grain growth of Y123, affecting the superconducting properties of the samples. On the other hand, the intergranular critical current density, Jcm, was found to increase with graphene nanoparticle addition and had the highest value at x = 1.0 wt.%, indicating that graphene nanoparticles acted as pinning centers in the Y123 matrix.

2018 ◽  
Vol 64 (4) ◽  
pp. 381
Author(s):  
Muhammad Tufiq Jamil ◽  
Javed Ahmad ◽  
Syed Hamad Bukhari ◽  
Murtaza Saleem

Rare earth nano sized pollycrystalline orthoferrites and orthocromites ReT mO3 (Re = La, Nd, Gd, Dy, Y and T m = Fe, Cr) have been synthesized by sol-gel auto combustion citrate method. The samples have been characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and UV-visible spectroscopy. The samples are single phase as confirmed by XRD analysis and correspond to the orthorhombic crystal symmetry with space group pbnm. Debye Scherer formula and Williamson Hall analysis have been used to calculate the average grain size which is consistent with that of determined from SEM analysis and varied between 25-75 nm. The elemental compositions of all samples have been checked by EDX analysis. Different crystallographic parameters are calculated with strong structural correlation among Re and Tm sites. The optical energy band gap has been calculated by using Tauc relation estimated to be in the range of 1.77 - 1.87 eV and 2.77 - 3.14 eV, for ReFeO3 and ReCrO3, respectively.


1999 ◽  
Vol 581 ◽  
Author(s):  
Q. Wei ◽  
C.M. Lieber

ABSTRACTA solution-based synthesis route was developed to produce large quantities of MgO nanorods. Hydrated basic magnesium chloride, which has needle-like crystal structure, was used as a precursor. A subsequent two-step transformation process with magnesium hydroxide as an intermediate product was used to preserve the morphology of the precursor to yield magnesium oxide nanorods. Scanning electron microscopy, powder X-ray diffraction and energy dispersive X-ray spectroscopy show that the products are very pure (>95%) crystalline MgO nanorods with diameters from 40 nm to 200 nm and lengths 10 microns or longer. High-resolution transmission electron microscopy and electron diffraction further reveal that these MgO nanorods are single crystals and that the rod axis is along the <110> crystal direction. A model for the structural transformation from hydrated basic magnesium chloride to magnesium oxide has been developed and compared to our experimental results. This solution-based process can be easily scaled-up, and is a low-cost source of pure magnesium oxide nanorods needed in many industrial applications, for example, as reinforcing agents in matrix composites and as flux-pinning centers in high-TC superconductors.


Author(s):  
Hongqiang Cui ◽  
Yongze Cao ◽  
Lei Zhang ◽  
Yuhang Zhang ◽  
Siying Ran ◽  
...  

Er3+ with different concentrations doped K2Yb(PO4)(MoO4) phosphors were prepared by a solid-state reaction method, and the layered orthorhombic crystal structure of the samples was confirmed by X-ray diffraction (XRD). Under...


2013 ◽  
Vol 829 ◽  
pp. 902-906 ◽  
Author(s):  
Mohammad Derakhshani ◽  
Hossein Abdizadeh ◽  
Mohammad Reza Golobostanfard

Recently photocatalytic materials have been used in variety of industrial applications. TiO2 is the only suitable photocatalytic material for industrial usage due to its benefits such as non-toxicity, stability, and low cost. TiO2 nanoparticles were successfully synthesized from titanium alkoxide precursor by sol-gel method. Effects of nitrogen doping on the microstructure and phase evolution of the TiO2 nanoparticles were investigated. The X-ray diffraction results of doped samples confirm the presence of anatase as the only crystalline phase. The addition of nitrogen in titania matrix leads to disappearance of rutile traces. The scanning electron microscopy show that TiO2 nanoparticle size decreases by increasing nitrogen doping. Furthermore, DSC-TG results reveal that the crystallization temperature of doped sample shifts to higher temperatures of about 100 °C.


2015 ◽  
Vol 1107 ◽  
pp. 291-294 ◽  
Author(s):  
Naif Mohammed Al-Hada ◽  
Elias B. Saion ◽  
Abdul H. Shaari ◽  
Mazliana A. Kamarudeen ◽  
Moayad Husein Flaifel ◽  
...  

Cadmium oxide (CdO) nanoparticles was synthesized from an aqueous solution containing metal nitrate as a precursor and polyvinyl pyrrolidone (PVP) as a capping agent by simple thermal-treatment method. The as-synthesized sample has been calcined at various temperatures from 500 to 650 °C to remove the organic matters. The structure and morphology of the calcined oxide nanoparticles have been examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The results obtained supports the fact that the thermal treatment method utilized for the synthesis of CdO nanoparticles is certainly a very simple and low cost technique that requires no additional chemicals.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Gedi Sreedevi ◽  
Kotte Tulasi Ramakrishna Reddy

Tin monosulphide (SnS) films have been successfully grown by a simple and low-cost wet chemical process, chemical bath deposition (CBD), using tin chloride and thioacetamide as precursors and tartaric acid as complexing agent. The layers were grown on glass substrate at different bath temperatures (Tb) that varied in the range 50–70°C. The energy dispersive X-ray analysis (EDAX) studies showed that all the grown films were nearly stoichiometric. The X-ray diffraction analysis indicated that the films had an intense peak at 31.6° that corresponds to the (111) plane of SnS and exhibited orthorhombic crystal structure. The intensity of (111) plane increases with the increase in bath temperature and became sharp at Tb=70°C, where the other crystal planes got suppressed, this indicates better crystallinity of the layers grown at this temperature. No other secondary phases of tin sulphide were observed. The structural parameters such as lattice constants and crystallite size were also calculated. The optical studies revealed that the layers had high optical absorption coefficient (>104 cm−1). The energy band gap was found to be allowed and direct and varied between 1.30 eV and 1.35 eV. The band gap decreased with the rise in bath temperature. The refractive index and the extinction coefficient were also evaluated. The details of these results will be presented and discussed.


Author(s):  
Ioana Sovago ◽  
Matthias J. Gutmann ◽  
Hans Martin Senn ◽  
Lynne H. Thomas ◽  
Chick C. Wilson ◽  
...  

Analysis of neutron and high-resolution X-ray diffraction data on form (III) of carbamazepine at 100 K using the atoms in molecules (AIM) topological approach afforded excellent agreement between the experimental results and theoretical densities from the optimized gas-phase structure and from multipole modelling of static theoretical structure factors. The charge density analysis provides experimental confirmation of the partially localized π-bonding suggested by the conventional structural formula, but the evidence for any significant C—N π bonding is not strong. Hirshfeld atom refinement (HAR) gives H atom positional and anisotropic displacement parameters that agree very well with the neutron parameters. X-ray and neutron diffraction data on the dihydrate of carbemazepine strongly indicate a disordered orthorhombic crystal structure in the space groupCmca, rather than a monoclinic crystal structure in space groupP21/c. This disorder in the dihydrate structure has implications for both experimental and theoretical studies of polymorphism.


2005 ◽  
Vol 20 (1) ◽  
pp. 1-6 ◽  
Author(s):  
V. G. Vlasenko ◽  
A. T. Shuvaev ◽  
D. S. Drannikov

New layered bismuth oxides Bi2(BiCaNa)m−1NbmO3m+3(m=2-4) with the Aurivillius type phase were successfully synthesized. The structures of the compounds have been studied by X-ray powder diffraction and refined by the Rietveld method. Bi2.25Ca0.5Na0.25Nb2O9(m=2) has an orthorhombic crystal structure with lattice constants a=5.4478(1) Å;b=5.4770(2) Å;c=24.883(8) Å, space group A21am (No. 36). Bi2CaNaNb3O12 and Bi2.25Ca0.5Na1.25Nb3O12(m=3) are orthorhombic with Fmmm(No. 69) space group and the unit-cell parameters a=5.4473(7) Å, b=5.4770(3) Å, c=32.722(6) Å and a=5.4574(7) Å, b=5.4884 (3) Å, c=32.711(6) Å, respectively. The structure of Bi2CaNa2Nb4O15(m=4) was found to be orthorhombic with parameters a=5.4584(8) Å, b=5.4833(3) Å, c=40.534(1) Å and was refined in the space group A21am (No. 36).


2019 ◽  
Vol 13 (02) ◽  
pp. 2050005
Author(s):  
Guisheng Liang ◽  
Xingxing Jin ◽  
Cihui Huang ◽  
Lijie Luo ◽  
Yongjun Chen ◽  
...  

Li3VO4 has gained significant attention as a promising anode material for lithium-ion batteries owing to its high specific capacity, low cost and safe working potential. Unfortunately, its disappointing electronic conductivity limits its rate performance. To address this problem, a series of Cr[Formula: see text]-doped Li3VO4 compounds are synthesized by solid-state reaction. The obtained Li[Formula: see text]Cr[Formula: see text]V[Formula: see text]O4 compounds ([Formula: see text] and 0.02) have the same orthorhombic crystal structure (Pnm21 space group), suggesting the successful Cr[Formula: see text] doping in Li3VO4. Compared with Li3VO4, Li[Formula: see text]Cr[Formula: see text]V[Formula: see text]O4 exhibits a two orders of magnitude larger electronic conductivity. Additional benefits of the Cr[Formula: see text] doping include the increase of the Li[Formula: see text] diffusion coefficient and the decrease of the particle size. Consequently, Li[Formula: see text]Cr[Formula: see text]V[Formula: see text]O4 displays not only a large reversible capacity (363[Formula: see text]mAh g[Formula: see text] at 60[Formula: see text]mA g[Formula: see text] and superior cyclic stability (86.6% capacity retention after 1000 cycles at 1200[Formula: see text]mA g[Formula: see text] but also decent rate performance (147[Formula: see text]mAh g[Formula: see text] at 1200[Formula: see text]mA g[Formula: see text].


Author(s):  
J.P. Goral ◽  
M.M. Al-Jassim ◽  
D. Albin ◽  
J.R. Tuttle ◽  
R. Noufi

Polycrystalline thin films of CuInSe2 and CuGaSe2 are currently being developed as low-cost photovoltaic devices. These films are vacuum-deposited onto molybdenum metallized alumina substrates. The film composition may be varied by manipulation of the deposition parameters. For photovoltaic applications, the desired phase has a stoichiometry close to CuInSe2. This compound is a zincblende variant, the cations and anions occupying separate fcc sublattices. Under certain growth conditions, the Cu and In atoms adopt an ordered configuration within the cationic sublattice resulting in the tetragonal chalcopyrite structure. Even when the deposition parameters are manipulated to produce nominally stoichiometric films, powder x-ray traces often exhibit anomalous peaks indicative of the presence of impurity phases. The identification of these minority phases by x-ray diffraction alone is not possible in this materials system due to low peak intensity and overlap considerations. The formation of the secondary phases has a detrimental effect on the electrical and optical properties of the thin film device.


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