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Full-Text Articles in Engineering
Dependence Of Magnetoelectric Properties On Sintering Temperature For Nano-Sic-Doped Mgb2/Fe Wires Made By Combined In Situ/Ex Situ Process, Wenxian Li, Rong Zeng, Jiazhao Wang, Y Li, S. X. Dou
Dependence Of Magnetoelectric Properties On Sintering Temperature For Nano-Sic-Doped Mgb2/Fe Wires Made By Combined In Situ/Ex Situ Process, Wenxian Li, Rong Zeng, Jiazhao Wang, Y Li, S. X. Dou
Faculty of Engineering - Papers (Archive)
Very fine nano-SiC particles (nm) were doped into a MgB2 superconductor. The influence of self-field supercurrent on the high-field performance of the nano-SiC-doped MgB2/Fe wires is discussed based on comparison of the critical current densities of the in situ processed nano-SiCdoped MgB2 wires and those of the nano-SiC-doped MgB2/Fe wires processed by the combination of in situ/ex situ methods.
Effect Of Thermal Strain On J(C) And T-C In High Density Nano-Sic Doped Mgb2, Wenxian Li, Rong Zeng, Lin Lu, S. X. Dou
Effect Of Thermal Strain On J(C) And T-C In High Density Nano-Sic Doped Mgb2, Wenxian Li, Rong Zeng, Lin Lu, S. X. Dou
Faculty of Engineering - Papers (Archive)
The influences of lattice strain on the superconducting critical current density Jc and critical transition temperature Tc in pure MgB2 and a SiC-MgB2 composite made by the diffusion process are explored, based on the thermal expansion coefficients and the low temperature effects on Raman scattering. The strong thermal strain provides a strong flux pinning force for the supercurrents at the interfaces between SiC and MgB2. The high Tc of SiC-MgB2 is also discussed according to the expanded lattice and Raman characteristics.
Influence Of Antimony Trioxide Nanoparticle Doping On Superconductivity In Mgb2 Bulk, Yun Zhang, S X. Dou
Influence Of Antimony Trioxide Nanoparticle Doping On Superconductivity In Mgb2 Bulk, Yun Zhang, S X. Dou
Faculty of Engineering - Papers (Archive)
In this work, antimony trioxide (Sb2O3) has been doped into MgB2 samples to act as an additive. The doping level varies from 2.5 to 15 wt%. The effects of Sb2O3 addition on the lattice parameters, critical temperature (Tc), critical current density (Jc), and upper critical field (Hc2) have been investigated in detail. It has been found that Sb2O3 doping results in a small depression in Tc. The Jc value is 2.4 × 103 A·cm−2 for …
Effect Of Mg/B Ratio On The Superconductivity Of Mgb2 Bulk With Sic Addition, Yun Zhang, S X. Dou, Cheng Lu, Sihai Zhou, Wenxian Li
Effect Of Mg/B Ratio On The Superconductivity Of Mgb2 Bulk With Sic Addition, Yun Zhang, S X. Dou, Cheng Lu, Sihai Zhou, Wenxian Li
Faculty of Engineering - Papers (Archive)
To improve the self-field critical current density (Jc) and critical temperature (Tc) in SiC-doped MgB2, optimization of the nominal Mg/B mixing ratio has been performed. The effects of the nominal Mg/B mixing ratio (x:2) on the superconductivity, Raman spectra, current transport properties, and flux pinning mechanisms in MgB2 with 10 wt.% SiC doping were investigated systematically, with x varied from 1 to 1.2. It has been found that the sample with the Mg/B ratio of 1.15:2 exhibited the best Jc performance for all fields (0–8.5 T), and its Tc was also …
Flux Pinning And Inhomogeneity In Magnetic Nanoparticle Doped Mgb2/Fe Wires, Nikolina Novosel, Damir Pajic, Mislav Mustapic, Emil Babic, Andrey Shcherbakov, Josip Horvat, Zeljko Skoko, Kreso Zadro
Flux Pinning And Inhomogeneity In Magnetic Nanoparticle Doped Mgb2/Fe Wires, Nikolina Novosel, Damir Pajic, Mislav Mustapic, Emil Babic, Andrey Shcherbakov, Josip Horvat, Zeljko Skoko, Kreso Zadro
Faculty of Engineering - Papers (Archive)
The effects of magnetic nanoparticle doping on superconductivity of MgB2/Fe wires have been investigated. Fe2B and SiO2-coated Fe2B particles with average diameters 80 and 150 nm, respectively, were used as dopands. MgB2 wires with different nanoparticle contents (0, 3, 7.5, 12 wt.%) were sintered at temperature 750°C. The magnetoresistivity and critical current density Jc of wires were measured in the temperature range 2–40 K in magnetic field B ≤ 16 T. Both transport and magnetic Jc were determined. Superconducting transition temperature Tc of doped wires decreases quite rapidly with …
"Organic" Mgb2-Xcx Superconductor With High Performance Enabled By Liquid Mixing Approach, Olga V. Shcherbakova, Alexey V. Pan, Emil Babic, S. X. Dou
"Organic" Mgb2-Xcx Superconductor With High Performance Enabled By Liquid Mixing Approach, Olga V. Shcherbakova, Alexey V. Pan, Emil Babic, S. X. Dou
Faculty of Engineering - Papers (Archive)
Comparative analysis of structural and electromagnetic characteristics have been performed on nano SiC- and polycarbosilane-doped MgB2 samples prepared by the dry and liquid mixing approaches. The total benefit of liquid mixing approach for fabrication of "organic" MgB2 superconductor with excellent electromagnetic performance has been demonstrated
Temperature Effect On Microstructure And Electromagnetic Performance Of Polycarbosilane And Sugar-Doped Mgb2 Wires, Andrey V. Shcherbakov, Josip Horvat, Olga V. Shcherbakova, Nikolina Novosel, Emil Babic, S. X. Dou
Temperature Effect On Microstructure And Electromagnetic Performance Of Polycarbosilane And Sugar-Doped Mgb2 Wires, Andrey V. Shcherbakov, Josip Horvat, Olga V. Shcherbakova, Nikolina Novosel, Emil Babic, S. X. Dou
Faculty of Engineering - Papers (Archive)
The effect of processing temperature on structural and superconducting properties of 10 wt.% sugar- and 10 wt.% PCS-doped MgB2 wires is systematically investigated. It is demonstrated that these dopants significantly enhance the electromagnetic performance of Fe-clad MgB2 superconductor and increase its potential for practical application. The enhancement of in-field critical current density (Jc(Ba)) and upper critical field (Bc2) is due to formation of a large amount of lattice defects caused by impurities and C substitution into the MgB2 crystal lattice. High temperature sintering of sugar-doped sample results …
Nanocoating Of Particles For Optimal Doping And Universal Enhancement Of Current-Carrying Ability In "Organic" Mgb2-Xcx Superconductors, Olga V. Shcherbakova, Alexey V. Pan, S X. Dou, Rashmi Nigam, David Wexler
Nanocoating Of Particles For Optimal Doping And Universal Enhancement Of Current-Carrying Ability In "Organic" Mgb2-Xcx Superconductors, Olga V. Shcherbakova, Alexey V. Pan, S X. Dou, Rashmi Nigam, David Wexler
Faculty of Engineering - Papers (Archive)
The universal approach of liquid mixing has been found to produce “organic” MgB2−xCx superconductors with structural and supercurrent-carrying properties unattainable by other techniques. We show by transmission electron microscopy combined with energy dispersive spectroscopy that these unique properties are enabled through coating of boron particles with a nanolayer of carbon. The subsequent reaction between carbon-encapsulated boron and magnesium results in enhanced carbon content x in the crystal lattice, as determined by x-ray diffraction pattern analysis. Among various carbon-containing compounds investigated, polycarbosilane has been found to be the optimal dopant for MgB2 superconductor, producing the largest …
Stress/Strain Induced Flux Pinning In Highly Dense Mgb2 Bulks, Rong Zeng, S X. Dou, Lin Lu, Wenxian Li, Chung-Kiak Poh, Jung Ho Kim, Josip Horvat, Dongqi Shi, Jianli Wang, Paul G. Munroe, X. F. Wang, Rongkun Zheng, S. P. Ringer, M Rindfleisch, Mike Tomsic
Stress/Strain Induced Flux Pinning In Highly Dense Mgb2 Bulks, Rong Zeng, S X. Dou, Lin Lu, Wenxian Li, Chung-Kiak Poh, Jung Ho Kim, Josip Horvat, Dongqi Shi, Jianli Wang, Paul G. Munroe, X. F. Wang, Rongkun Zheng, S. P. Ringer, M Rindfleisch, Mike Tomsic
Faculty of Engineering - Papers (Archive)
We have systematically studied the flux pinning behavior of MgB2 bulks synthesized by direct diffusion of Mg into pressed pellets of high purity crystalline B powder, with and without mixing with C and SiC nanoparticles, at a reaction temperature of 850degC for 10 hrs. All of the samples showed very high purity and high density, but their microstructure and flux pinning behavior showed significant differences. It was found that the pure MgB2 agrees with the deltaTc pinning model, nano-C doped MgB2 agrees with the deltal pinning model, while the SiC+MgB2 composite agrees …
Increased Superconductivity For Cnt Doped Mgb2 Sintered In 5t Pulsed Magnetic Field, Wenxian Li, Ying Li, Rong Hua Chen, Rong Zeng, Lin Lu, Yun Zhang, Michael Tomsic, Matthew Rindfleisch, S. X. Dou
Increased Superconductivity For Cnt Doped Mgb2 Sintered In 5t Pulsed Magnetic Field, Wenxian Li, Ying Li, Rong Hua Chen, Rong Zeng, Lin Lu, Yun Zhang, Michael Tomsic, Matthew Rindfleisch, S. X. Dou
Faculty of Engineering - Papers (Archive)
The superconductivity of carbon nanotube (CNT) doped MgB2 sintered in pulsed magnetic field (PMF) was investigated with Raman scattering measurements and Raman spectral fit analysis. Although the carbon (C) substitution for the boron (B) is increased for the sample sintered in PMF, its superconductivity is advanced comparing with the sample sintered without PMF. The improved critical transition temperature, Tc, is attributed to the strengthening of the electron-phonon coupling (EPC) in MgB2, as reflected by the broadened E 2g mode in the Raman spectra, because the carbon atoms are homogeneously distributed in the boron planes.
Influence Of Heat Treatment On Superconductivity Of Mgb2 Bulk Sintered In Flowing Welding Grade Ar Atmosphere, Yun Zhang, Cheng Lu, Sihai Zhou, K. C. Chung, Y. K. Kim, S. X. Dou
Influence Of Heat Treatment On Superconductivity Of Mgb2 Bulk Sintered In Flowing Welding Grade Ar Atmosphere, Yun Zhang, Cheng Lu, Sihai Zhou, K. C. Chung, Y. K. Kim, S. X. Dou
Faculty of Engineering - Papers (Archive)
In this paper, MgB2 samples were sintered in flowing welding grade Ar. The effect of the sintering time varying from 10 minutes to 3 hours on superconductivity of MgB2 has been investigated. It has been found that both Hc2 and Hirr increase with the sintering time and they have linear relationships with microstrain. The sample sintered for 30 min exhibits the highest Jc at high fields. The reason can be attributed to the improved connectivity and the increased Hc2.
Thermal-Strain-Induced Enhancement Of Electromagnetic Properties Of Sic-Mgb2 Composites, Rong Zeng, S X. Dou, Lin Lu, Wenxian Li, Jung Ho Kim, Paul G. Munroe, Rongkun Zheng, S P. Ringer
Thermal-Strain-Induced Enhancement Of Electromagnetic Properties Of Sic-Mgb2 Composites, Rong Zeng, S X. Dou, Lin Lu, Wenxian Li, Jung Ho Kim, Paul G. Munroe, Rongkun Zheng, S P. Ringer
Faculty of Engineering - Papers (Archive)
The effect of thermal strain caused by the different thermal expansion coefficients (α) of the MgB2 and SiC phases on the electromagnetic properties was studied for SiC–MgB2 composite, which was made by premixing SiC and B, followed by Mg diffusion and reaction. Thermal strain in the MgB2 phase was demonstrated with x-ray diffraction, Raman spectroscopy, and transmission electron microscopy. In contrast to the common practice of improving the critical current density Jc and the upper critical field Hc2 of MgB2 through chemical substitution, by taking advantage of residual thermal strains, we …
A Comparative Study On Field, Temperature, And Strain Dependences Of The Critical Current For Doped And Undoped Mgb2 Wires Based On The Percolation Model, Sangjun Oh, Jung Ho Kim, Kyuhwan Cho, Chulhee Lee, Chan-Joong Kim, S. X. Dou, M Rindfleisch, Mike Tomsic, Jung-Ho Ahn
A Comparative Study On Field, Temperature, And Strain Dependences Of The Critical Current For Doped And Undoped Mgb2 Wires Based On The Percolation Model, Sangjun Oh, Jung Ho Kim, Kyuhwan Cho, Chulhee Lee, Chan-Joong Kim, S. X. Dou, M Rindfleisch, Mike Tomsic, Jung-Ho Ahn
Faculty of Engineering - Papers (Archive)
Field, temperature, and strain dependences of the critical current for a SiC doped multifilamentary in situ MgB2 wire have been studied. Measurement results were compared with that of the undoped wire, and the origin of the difference in the critical current is discussed. The critical current can be calculated with the percolation model considering the effect of anisotropy. The temperature dependence of the fitting parameters, the upper critical field along the ab-plane, and c-axis is compared with the dirty-limit two-gap theory. To assess the validity of the fitting parameters, resistive transition has been measured especially to …
Preparing Mgb2 With Excessive Mg Environment Sintering And Two-Step Sintering Approach, S X. Dou, Sihai Zhou, Alexey V. Pan, Jaimoo Yoo, Yun Zhang, Kookchae Chung
Preparing Mgb2 With Excessive Mg Environment Sintering And Two-Step Sintering Approach, S X. Dou, Sihai Zhou, Alexey V. Pan, Jaimoo Yoo, Yun Zhang, Kookchae Chung
Faculty of Engineering - Papers (Archive)
MgB2 superconductors were made with two processes in this work. In one case, the SiC doped MgB2 pellets were sintered in excessive Mg medium. It is found that the samples sintered in excessive Mg medium present Mg-rich composition comparing with the one sintered in Ar gas. The density is higher and the resistance is lower due to the penetration of the Mg into the pores and grain boundary of MgB2, which is beneficial to the Jc improvement. In the other case, a two-step process was employed to make MgB2. Jc of the …
Raman Study Of Element Doping Effects On The Superconductivity Of Mgb2, Wenxian Li, Yongqing Li, R H. Chen, Rong Zeng, S. X. Dou, M Y. Zhu, H M. Jin
Raman Study Of Element Doping Effects On The Superconductivity Of Mgb2, Wenxian Li, Yongqing Li, R H. Chen, Rong Zeng, S. X. Dou, M Y. Zhu, H M. Jin
Faculty of Engineering - Papers (Archive)
The influences of phonon frequency and unit cell volume on the superconductivity of element-doped MgB2 are discussed with reference to a Raman study on SiC, C, Mn, and Al-Ag-doped Mg-B materials. A phenomenon has been found in the doped samples, in that the phonon frequency changes to counteract the crystal lattice variation to keep the system stable within a Grüneisen parameter of 2.0–4.0. The chemical doping effects on phonon frequency and unit cell volume can be explained by the harmonicity-anharmonicity competition in the compounds. A decreased electronic density of states is responsible for the depression of superconductivity that is …
Effects Of C Substitution On The Pinning Mechanism Of Mgb2, Jianli Wang, Rong Zeng, Jung Ho Kim, Lin Lu, S. X. Dou
Effects Of C Substitution On The Pinning Mechanism Of Mgb2, Jianli Wang, Rong Zeng, Jung Ho Kim, Lin Lu, S. X. Dou
Faculty of Engineering - Papers (Archive)
The temperature and magnetic field of the critical current density of four selected pure and C-doped MgB2 samples have been investigated in detail and the flux pinning mechanism has been analyzed. It was found that the sintering temperature and the substitution of carbon can significantly modify the flux pinning mechanism. Below 30 K, the reduced field dependences of the reduced pinning force for all investigated samples were found to closely obey one scaling law, reflecting the presence of only one dominant pinning mechanism. A delta T-c pinning mechanism was found to be mainly responsible in pure MgB2 samples while the …
Improvement Of Jc And Hc2 In Mgb2 Superconductor With Citric Acid Addition, Rong Zeng, Lin Lu, Jianli Wang, Wenxian Li, Dongqi Shi, Josip Horvat, S. X. Dou
Improvement Of Jc And Hc2 In Mgb2 Superconductor With Citric Acid Addition, Rong Zeng, Lin Lu, Jianli Wang, Wenxian Li, Dongqi Shi, Josip Horvat, S. X. Dou
Faculty of Engineering - Papers (Archive)
This paper reports on the fabrication and characterization of citric acid (CA)-C6H8O7 added MgB2 superconductor. The relationships between microstructures, critical current density (Jc), critical temperature (Tc), upper critical field (Hc2), irreversibility field (Hirr), and normal state resistivity for 10 wt% C6H8O7 added MgB2 samples sintered at temperatures from 650C to 950C were systematically studied. A reduction in Tc and in lattice parameter a due to the C substitution and possible oxygen (O) effects occurs wtih C6H8O7 addition. Jc, Hc2, and Hirr are significantly enhanced, however, with the addition of C6H8O7. All the samples exhibit Jc above 104 A/cm2 at 5 …
Effects Of Sintering Atmosphere On The Superconducting Properties Of Sic Doped Bulk Mgb2 Superconductor, Sihai Zhou, Alexey V. Pan, Yun Zhang, S. X. Dou
Effects Of Sintering Atmosphere On The Superconducting Properties Of Sic Doped Bulk Mgb2 Superconductor, Sihai Zhou, Alexey V. Pan, Yun Zhang, S. X. Dou
Faculty of Engineering - Papers (Archive)
A study was conducted to investigate the effects of the sintering atmosphere on the superconducting properties of SiC doped MgB2 superconductors. Four different purity Ar gases were chosen as the sintering atmosphere for making bulk samples. It was found that the impurities in the Ar gas resulted in different leves of MgO in the resultant MgB2 superconductors. Superconducting properties, such as the critical temperature (Tc), critical current density (Jc) and upper critical field (Hc2) were affected by the impurity phase inside the samples. Sample phase composition and morphology were analysed to explain the effect of the sintering atmosphere on the …
Identification Of Factors Limiting The Critical Current Density In Mgb2 _Xcx Superconductors At Low Magnetic Fields, Olga V. Shcherbakova, Alexey V. Pan, Jianli Wang, Andrey Shcherbakov, S. X. Dou, David Wexler
Identification Of Factors Limiting The Critical Current Density In Mgb2 _Xcx Superconductors At Low Magnetic Fields, Olga V. Shcherbakova, Alexey V. Pan, Jianli Wang, Andrey Shcherbakov, S. X. Dou, David Wexler
Faculty of Engineering - Papers (Archive)
Structural analysis and electromagnetic measurements have been performed on a range of samples prepared by the liquid mixing approach to doping MgB2 are sugar, malic acid, and polycarbosilane. The results obtained have allowed us to clarify the contributions of the factors limiting critical current at low magnetic fields in doped MgB2.
Mechanism Of Enhancement In Electromagnetic Properties Of Mgb2 By Nano Sic Doping, S X. Dou, Olga V. Shcherbakova, W. K. Yeoh, J. H. Kim, Saeid Soltanian, Xiaolin Wang, C. Senatore, R. Flukiger, M. Dhalle, O. Husnjak, E. Babic
Mechanism Of Enhancement In Electromagnetic Properties Of Mgb2 By Nano Sic Doping, S X. Dou, Olga V. Shcherbakova, W. K. Yeoh, J. H. Kim, Saeid Soltanian, Xiaolin Wang, C. Senatore, R. Flukiger, M. Dhalle, O. Husnjak, E. Babic
Faculty of Engineering - Papers (Archive)
A comparative study of pure, SiC, and C doped MgB2 wires has revealed that the SiC doping allowed C substitution and MgB2 formation to take place simultaneously at low temperatures. C substitution enhances Hc2, while the defects, small grain size, and nanoinclusions induced by C incorporation and low-temperature processing are responsible for the improvement in Jc. The irreversibility field (Hirr) for the SiC doped sample reached the benchmarking value of 10 T at 20 K, exceeding that of NbTi at 4.2 K. This dual reaction model also enables us to predict desirable …
Superconducting Properties Of Mgb2: Polycarbosilane Versus Conventional Nano-Sic Doping, Olga V. Shcherbakova, Alexey V. Pan, David Wexler, S. X. Dou
Superconducting Properties Of Mgb2: Polycarbosilane Versus Conventional Nano-Sic Doping, Olga V. Shcherbakova, Alexey V. Pan, David Wexler, S. X. Dou
Faculty of Engineering - Papers (Archive)
The effect of polycarbosilane (PCS) doping on the superconducting properties of MgB2 was systematically investigated. Highly reactive C and Si appeared after PCS decomposition facilitating incorporation of C into the MgB2 lattice, as well as the reaction between Si and Mg, resulting in formation of a large number of small Mg2Si particles within MgB2 grains. C-substitution induced crystal lattice defects and impurities act as strong pinning centers, significantly improving Jc(Ba) performance in the high field region. The differences in the effects of SiC and PCS doping have been studied and are described to the structural transformation that occurs in MgB2 …
Specific Heat And Magnetic Relaxation Analysis Of Mgb2 Bulk Samples With And Without Additives, C. Senatore, P. Lezza, R. Lortz, Olga V. Shcherbakova, Wai Kong Yeoh, S. X. Dou, R. Flukiger
Specific Heat And Magnetic Relaxation Analysis Of Mgb2 Bulk Samples With And Without Additives, C. Senatore, P. Lezza, R. Lortz, Olga V. Shcherbakova, Wai Kong Yeoh, S. X. Dou, R. Flukiger
Faculty of Engineering - Papers (Archive)
The effects of SiC and Carbon doping on the superconducting properties of MgB2 polycrystalline samples have been analysed by means of specific heat and magnetic relaxation measurements. It is known that the addition of nanometric powders of SiC and C leads to the enhancement of Birr and Jc. However, the underlying physical mechanism is not completely understood. Magnetic relaxation measurements did not show detectable effects of both the additions on the pinning properties of MgB2. It follows that doping acts mainly introducing disorder into the superconductor and thus raising Bc2. In the case of MgB1.9C0.1, specific heat measurements show that …
Improvement Of Upper Critical Field And Critical Current Density In Single Walled Cnt Doped Mgb2=Fe Wires, J. H. Kim, W. K. Yeoh, X. Xu, Dongqi Shi, S. X. Dou
Improvement Of Upper Critical Field And Critical Current Density In Single Walled Cnt Doped Mgb2=Fe Wires, J. H. Kim, W. K. Yeoh, X. Xu, Dongqi Shi, S. X. Dou
Faculty of Engineering - Papers (Archive)
We evaluated the doping effect of single walled carbon nanotubes (SWCNT) on the phase formation, microstructure, critical current density ( ), and upper critical field ( 2) of MgB2 superconductor. All samples were sintered at temperatures ranging from 650 to 1000 C for 30 min. A typical high sintering temperature (900 C) sample was composed of well-consolidated MgB2 grain of 100 to 200 nm and nanosized particles, resulting in enhancement of and 2. This indicates that lattice defects and microstructural change have occurred as a result of carbon (C) coming from SWCNT. On the other hand, a sample sintered at …
Magnetic Field Processing To Enhance Critical Current Densities Of Mgb2 Superconductors, S X. Dou, Wai Kong Yeoh, Olga V. Shcherbakova, Josip Horvat, Jung Ho Kim, Alexey V. Pan, David Wexler, Yongqing Li, W X. Li, Z M. Ren, Paul G. Munroe, J Z. Cui
Magnetic Field Processing To Enhance Critical Current Densities Of Mgb2 Superconductors, S X. Dou, Wai Kong Yeoh, Olga V. Shcherbakova, Josip Horvat, Jung Ho Kim, Alexey V. Pan, David Wexler, Yongqing Li, W X. Li, Z M. Ren, Paul G. Munroe, J Z. Cui
Faculty of Engineering - Papers (Archive)
A magnetic field of up to 12T was applied during the sintering process of pure MgB2 and carbon nanotube(CNT)dopedMgB2wires. The authors have demonstrated that magnetic field processing results in grain refinement, homogeneity, and enhancement in Jc(H) and Hirr. The extent of improvement in Jc increases with increasing field. The Jc for a 10T field processed CNTdoped sample increases by a factor of 3 at 10K and 8T and at 20K and 5T, respectively. Hirr for the 10T field processed CNTdoped sample reached 9T at 20K, which exceeded the best value of SiC dopedMgB2 at 20K. Magnetic field processing reduces the …
Uranium Doping And Thermal Neutron Irradiation Flux Pinning Effects In Mgb2, Tania M. Silver, J. Horvat, M. Reinhard, P. Yao, S. Keshavarzi, P. Munroe, S. X. Dou
Uranium Doping And Thermal Neutron Irradiation Flux Pinning Effects In Mgb2, Tania M. Silver, J. Horvat, M. Reinhard, P. Yao, S. Keshavarzi, P. Munroe, S. X. Dou
Faculty of Engineering - Papers (Archive)
The U/n method is a well-established means of improving flux pinning and critical current performance in cuprate superconductors. The method involves the doping of the superconductor with 235U followed by irradiation with thermal neutrons to promote fission. The resultant columnar damage tracks produced by the energetic fission products pin flux vortices and improve critical current performance in magnetic fields. No such improvement could be observed when the U/n method was applied to the MgB2 superconductor. No fission tracks could be observed in TEM, even for samples that were irradiated at the highest fluence. Gamma-ray spectroscopy indicated that fission had occurred …