Short Review on Rare Earth and Metalloid Oxide Additions to MgB2 as a Candidate Superconducting Material for Medical Applications

2015 ◽  
Vol 638 ◽  
pp. 357-362 ◽  
Author(s):  
Dan Batalu ◽  
Gheorghe Aldica ◽  
Mihail Burdusel ◽  
Petre Badica
Keyword(s):  
Magnetic Field ◽  
Rare Earth ◽  
Critical Temperature ◽  
Critical Current Density ◽  
Strong Influence ◽  
Short Review ◽  
Medical Applications ◽  
Superconducting Properties ◽  
Magnetic Coils ◽  
Complex Optimization

MgB2 is a candidate for the fabrication of magnetic coils used in medical applications. Our review indicate that oxide additions based on the rare earth or metalloid elements show improvement of the MgB2 critical current density (Jc) and the irreversible magnetic field (Hirr) without significantly affecting the critical temperature (Tc) However, the characteristics of the additions and the technological approaches show a strong influence in controlling superconducting properties. Both additions and the technology need a careful and complex optimization in order to enhance the Jc and Hirr.

Porosity Effect on Superconducting Properties of YBa2Cu3Oδ and YCaBa4Cu6Oδ

2015 ◽  
Vol 1107 ◽  
pp. 601-605
Author(s):  
S.A. Senawi ◽  
H. Azhan ◽  
W.N.F.W. Zainal ◽  
W.A.W. Razali ◽  
A. Nazree ◽  
...  
Keyword(s):  
Critical Temperature ◽  
Critical Current Density ◽  
Porous Structure ◽  
Critical Current ◽  
Current Density ◽  
Resistivity Measurement ◽  
Effective Cross Section ◽  
Ceramic Materials ◽  
Solid State Reaction Method ◽  
Superconducting Properties

This paper reports on the properties of YBa2Cu3Od (Y123) and YCaBa4Cu6Oy (Y146) with non-porous and porous structures. The relationship between calcium doping and critical temperature (Tc) was studied to determine the optimal superconducting properties. A series of heating and grinding via solid state reaction method was used to fabricate the ceramic materials. The electrical properties were investigated via critical temperature, TC and critical current density, JC using the resistivity measurement system (RMS). Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) were used to analyze the material morphology and structure, respectively. The orthorhombicity increased due to less porosity of the samples. The calcium presence partially replaced larger Ba(II) site and degraded orthorhombicity. The highest critical current density (JC) was porous YCaBa2Cu3Oy which was 2.32 A/cm2 compared to 0.75 A/cm2 for porous YCaBa4Cu6Oy at 60 K. The critical temperature for porous structure was less than non porous structure for Ca doped Y146 system which was 69.9 K and 67.9 K. SEM micrograph unveiled that the Jc was induced significantly by continuity of grain formation via grain size. Pores homogenized the grains surface quality and connectivity due to strain release thus increasing effective cross section of the sample for current density (Jc) over the vast areas.

scholarly journals Температурные зависимости критических параметров неоднородных сверхпроводящих пленок

2021 ◽  
Vol 63 (8) ◽  
pp. 1035
Author(s):  
П.И. Безотосный ◽  
К.А. Дмитриева
Keyword(s):  
Magnetic Field ◽  
Critical Temperature ◽  
External Magnetic Field ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Superconducting Films ◽  
Critical Magnetic Field ◽  
Temperature Dependences ◽  
Comparison Of The Results

The results of calculating the temperature dependences of the critical current density and critical magnetic field of thin inhomogeneous superconducting films are presented. Comparison of the results obtained for inhomogeneous films with the results of calculations for homogeneous ones showed that in both cases, the decrease in the critical magnetic field occurs according to the root law, and the critical current density changes according to a power law with a degree of 3/2 when approaching the critical temperature. Quantitatively, the critical current density for inhomogeneous films in the absence of an external magnetic field is lower than for homogeneous ones. In turn, the critical magnetic field of inhomogeneous films is much larger than the critical field of homogeneous films.

Relation of Constituents with Superconducting Characteristics in Low-Temperature-Preheated YBCO Ceramics

1992 ◽  
Vol 275 ◽  
Author(s):  
Junya Nishino ◽  
Hiroaki Nishikawa ◽  
Muneo Ayabe ◽  
Yuji Ikegami
Keyword(s):  
Critical Temperature ◽  
Low Temperature ◽  
Critical Current Density ◽  
Superconducting Properties ◽  
Ybco Bulk ◽  
Disordered Phase ◽  
Yttrium Barium ◽  
Ybco Ceramics ◽  
Critical Current Density Jc ◽  
Critical Temperature Tc

ABSTRACTYBCO bulk ceramics pre-heated at low temperature before sintering were studied on the structure and superconducting properties mainly by varying the concentration of Ba/Y ratio.At 15.8–16.2wt% of the oxygen content Oc calcurated from the compositions of yttrium, barium and copper on the assumption that the valence of copper is 2, (123) phase is main and critical temperature(Tc) and critical current density(Jc) reach to 88–90K and about 103A/cm2, respectively.It is presumed that there is a possibility of the exixtence of oxygen deficient and disordered phase in addition to (123) and (211) phases and BaCuO2.

THE MAGNETIC AND ELECTRICAL PROPERTIES OF RARE-EARTH Sm3+ SUBSTITUTED Bi1.7Pb0.3Sr2Ca2-xSmxCu3O12 SYSTEM

2005 ◽  
Vol 19 (06) ◽  
pp. 331-340 ◽  
Author(s):  
AHMET EKİCİBİL ◽  
ATILLA COŞKUN ◽  
BEKIR ÖZÇELİK ◽  
KERIM KIYMAÇ
Keyword(s):  
Magnetic Field ◽  
Rare Earth ◽  
Hole Concentration ◽  
Superconducting Properties ◽  
Rare Earth Ion ◽  
Different Temperatures ◽  
Ion Substitution ◽  
Trivalent Rare Earth ◽  
Increasing Temperature ◽  
Magnetic Nature

In the present work, the magnetic properties of high-Tc Bi 1.7 Pb 0.3 Sr 2 Ca 2-x Sm x Cu 3 O 12 system (x = 0.03) have been investigated, for different temperatures below Tc. Substitution of Sm 3+ for Ca 2+ is found to change the superconducting properties of the system, despite the weak paramagnetic nature of the Sm 3+ ion. The dc magnetization measurements performed on the compound reveal that the superconducting regions decrease with increasing temperature and magnetic field. The results are explained on the basis of a possible reduction of hole concentration with trivalent rare-earth ion substitution, and also on the basis of the magnetic nature of the substituted Sm 3+ ions.

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.

scholarly journals Theoretical Derivation of Critical Current Density and Critical Magnetic Field Considering Many-Body Interactions of Magnetic Flux Quanta

2021 ◽  
Author(s):  
Shinichi Ishiguri
Keyword(s):  
Magnetic Field ◽  
Critical Temperature ◽  
Magnetic Flux ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Critical Magnetic Field ◽  
Many Body ◽  
Magnetic Flux Quantum ◽  
Many Body Interactions

To clarify the relationships among critical temperature, critical magnetic field, and critical current density, this paper describes many-body interactions of quantum magnetic fluxes (i.e., vortices) and calculates pinning-related critical current density. All calculations are analytically derived, without numerical or fitting methods. After calculating a magnetic flux quantum mass, we theoretically obtain the critical temperature in a many-body interaction scenario (which can be handled by our established method). We also derive the critical magnetic field and inherent critical current density at each critical temperature. Finally, we determine the pinning-related critical current density with self-fields. The relationships between the critical magnetic field and critical temperature, inherent critical current density and critical temperature, and pinning critical current density and self-magnetic field were consistent with experimental observations. From the critical current density and critical magnetic field, we clarified the magnetic field transition. It appears that a magnetic flux quantum collapses when the lattice of magnetic flux quanta melts. Our results, combined with our previously published papers, provide a comprehensive understanding of the transition points in high-Tc cuprates.

Effect of Nano-Sized Sm2BaCuO5 Particles Addition on the Pinning Mechanism of Sm–Ba–Cu–O Materials

2004 ◽  
Vol 19 (3) ◽  
pp. 843-850 ◽  
Author(s):  
Shih-Yun Chen ◽  
Ping-Chi Hseih ◽  
In-Gann Chen ◽  
Mow-Kuen Wu
Keyword(s):  
Critical Temperature ◽  
Magnetic Fields ◽  
Critical Current Density ◽  
The Other ◽  
High Magnetic Fields ◽  
Superconducting Properties ◽  
Pinning Mechanism ◽  
Pinning Centers ◽  
Crystalline Defects ◽  
Control Samples

The superconducting properties of air-processed melt-textured growth Sm–Ba–Cu–O samples with addition of small amounts (0.004 wt%, 0.4 wt%, 4 wt%) of nano-sized Sm2BaCuO5 particles (nm211) were studied. The microstructure observations show that the size distribution and morphology of the 211-particles of the nm211-doped samples are similar to that of the control (undoped) samples. However, except for the 4 wt% nm211-doped sample, both Tc (critical temperature) and Jc (H, T) (critical current density) are enhanced in nm211-doped samples, and the Jc–H curves are different from those of control samples. The effect of nm211 particles on Jc enhancement is larger at high magnetic fields (>1 T at 77 K) than at low magnetic fields (0∼1 T). The dominant pinning mechanism by analyzing the Jc (H, T) data using the scaling theory indicate that the nm211-doped samples are originated from Δκ pinning (i.e., Tc variation); on the other hand, the control samples are originated from normal pinning (i.e., nonsuperconducting crystalline defects). It is proposed that nano-sized compositional fluctuations in the RE1+x Ba2−x Cu3O y matrix, which are products of nm211 particles and liquid peritectic reaction, act as the source of Δκ pinning centers.

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