Study of dynamic behaviors for nano Fe-doped MgB2 superconductor via ac-susceptibility measurements

Ansari, Intikhab A.

doi:10.1016/j.ceramint.2018.10.025

Cited by 14 publications

(10 citation statements)

References 25 publications

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“…These materials comprise dopants and additives, such as carbon, [7][8][9][10][11][12][13][14] silver, etc. [6,[15][16][17][18][19][20][21] Dopants interact with lattice, whereas additives form secondary phases, both acting then as pinning centers. These substituents were added to the solid mixture of Mg and B powders, rigorously mixed before sintering.…”

Section: Introductionmentioning

confidence: 99%

Optimization of Carbon Encapsulated Boron Doping for High‐Performance Bulk Sintered MgB₂

et al. 2020

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Carbon has been a standard doping agent in MgB 2 for long time. It, however, has also participated in a non-uniform distribution of the constituents throughout the bulk MgB 2. To address this issue, carbon encapsulated boron (CEB) was used instead of the manually added mixture of boron and carbon. The previous studies confirmed that only low concentrations of carbon in CEB were effective for synthesis of a high-performance bulk MgB 2. Here, a further step in optimization carbon content in CEB is reported. Carbon content in CEB varied as 1, 1.1, 1.35, 1.5, and 1.9 wt%. X-ray diffraction (XRD) results depict a slight shift in peaks corresponding to a-b plane, indicating carbon substitution into the lattice. High superconducting critical current density in self-field, such as 660, 550, and 435 kA cm À2 , was observed in the samples with 1.5 wt% CEB at 10, 15, and 20 K, respectively. In addition, J c of 75 kA cm À2 at 2 T and 20 K was observed in the 1.5 wt% CEB sample, which is thrice the value observed in the pure sample, with a minute tradeoff in T c (around 37.5 K). Scanning electron microscope (SEM) images reveal that small particles of size ranging from 50 to 200 nm contribute to J c improvement. Energy-dispersive X-ray (EDX) results show carbon uniformly distributed throughout the bulk.

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Section: Introductionmentioning

confidence: 99%

Optimization of Carbon Encapsulated Boron Doping for High‐Performance Bulk Sintered MgB₂

et al. 2020

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Section: Resultsmentioning

confidence: 99%

“…This demonstrates that nano Fe-and Co-doped samples contain tiny grains and imperfect crystallinity. The Scherrer's equation is applied to calculate the average particle size (D) of the nanoparticles for each sample (peak 101) where k = 0.94 is the shape factor of a particle, presuming shape of the nanoparticles as sphere, λ = 1.5406 Å the wavelength of Cu Kα radiation, β is the FWHM of the XRD (101) peak, and θ is the diffraction angle of the peak 43 . A glance at the table points out that the average grain size of the parent MgB 2 is about 29 nm.…”

Section: Resultsmentioning

confidence: 99%

Metal doped layered MgB2 nanoparticles as novel electrocatalysts for water splitting

Sadeghi

Peighambardoust

Khatamian

et al. 2021

Sci Rep

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Growing environmental problems along with the galloping rate of population growth have raised an unprecedented challenge to look for an ever-lasting alternative source of energy for fossil fuels. The eternal quest for sustainable energy production strategies has culminated in the electrocatalytic water splitting process integrated with renewable energy resources. The successful accomplishment of this process is thoroughly subject to competent, earth-abundant, and low-cost electrocatalysts to drive the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), preferably, in the same electrolyte. The present contribution has been dedicated to studying the synthesis, characterization, and electrochemical properties of newfangled electrocatalysts with the formal composition of Mg1−xTMxB2 (x = 0.025, 0.05, and 0.1; TM (transition metal) = Fe and Co) primarily in HER as well as OER under 1 M KOH medium. The electrochemical tests revealed that among all the metal-doped MgB2 catalysts, Mg0.95Co0.05B2 has the best HER performance showing an overpotential of 470 mV at − 10 mA cm−2 and a Tafel slope of 80 mV dec−1 on account of its high purity and fast electron transport. Further investigation shed some light on the fact that Fe concentration and overpotential for HER have adverse relation meaning that the highest amount of Fe doping (x = 0.1) displayed the lowest overpotential. This contribution introduces not only highly competent electrocatalysts composed of low-cost precursors for the water-splitting process but also a facile scalable method for the assembly of highly porous electrodes paving the way for further stunning developments in the field.

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“…However, there were secondary phases at 2θ of 32.54°, 37.7°, and 45.08° which were assigned to the FeB phase. It is remarkable to mention that the impurity peak at 45.08° (labeled by ) can also be related to Fe2B, especially at high concentration doping of Fe (x = 0.1) 43 . The minor amount of impurities with infinitesimal peaks indicated that the substitution of Co and Fe for Mg has significantly suppressed the amount of Mg and MgO formation.…”

Section: Resultsmentioning

confidence: 99%

“…This demonstrates that nano Fe-and Co-doped samples contain tiny grains and imperfect crystallinity. The Scherrer's equation is applied to calculate the average particle size (D) of the nanoparticles for each sample (peak 101) D = ( λ) ⁄ ( ) where k = 0.94 is the shape factor of a particle, presuming shape of the nanoparticles as sphere,  = 1.5406 Å the wavelength of Cu K radiation,  is the FWHM of the XRD (101) peak, and  is the diffraction angle of the peak 43 . A glance at the table points out that the average grain size of the parent MgB2 is about 29 nm.…”

Section: Resultsmentioning

confidence: 99%

Metal Doped Layered MgB2 Nanoparticles as Novel Electrocatalysts for Water Splitting

Sadeghi

Peighambardoust

Khatamian

et al. 2020

Preprint

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Growing environmental problems along with the galloping rate of population growth have raised an unprecedented challenge to look for an ever-lasting alternative source of energy for fossil fuels. The eternal quest for sustainable energy production strategies has culminated in the electrocatalytic water splitting process integrated with renewable energy resources. The successful accomplishment of this process is thoroughly subject to highly efficient, earth-abundant, and cost-effective electrocatalysts to drive the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), preferably, in the same electrolyte. The present contribution has been dedicated to studying the synthesis, characterization, and electrochemical properties of newfangled electrocatalysts with the formal composition of Mg1-xTmxB2 (x = 0.025, 0.05, and 0.1; Tm (transition metal) = Fe and Co) primarily in HER as well as OER under 1 M KOH medium. The electrochemical tests revealed that among all the metal-doped MgB2 catalysts, Mg0.95Co0.05B2 has the best HER performance showing an overpotential of 470 mV at -10 mA cm-2 and a Tafel slope of 80 mV dec-1 on account of its high purity and fast electron transport. Further investigation shed some light on the fact that Fe concentration and overpotential for HER have adverse relation meaning that the highest amount of Fe doping (x = 0.1) displayed the lowest overpotential. This contribution introduces not only highly competent electrocatalysts composed of low-cost precursors for the water-splitting process but also a facile scalable method for the assembly of highly porous electrodes paving the way for further stunning developments in the field.

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Study of dynamic behaviors for nano Fe-doped MgB2 superconductor via ac-susceptibility measurements

Cited by 14 publications

References 25 publications

Optimization of Carbon Encapsulated Boron Doping for High‐Performance Bulk Sintered MgB₂

Optimization of Carbon Encapsulated Boron Doping for High‐Performance Bulk Sintered MgB₂

Metal doped layered MgB2 nanoparticles as novel electrocatalysts for water splitting

Metal Doped Layered MgB2 Nanoparticles as Novel Electrocatalysts for Water Splitting

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Study of dynamic behaviors for nano Fe-doped MgB2 superconductor via ac-susceptibility measurements

Cited by 14 publications

References 25 publications

Optimization of Carbon Encapsulated Boron Doping for High‐Performance Bulk Sintered MgB2

Optimization of Carbon Encapsulated Boron Doping for High‐Performance Bulk Sintered MgB2

Metal doped layered MgB2 nanoparticles as novel electrocatalysts for water splitting

Metal Doped Layered MgB2 Nanoparticles as Novel Electrocatalysts for Water Splitting

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Optimization of Carbon Encapsulated Boron Doping for High‐Performance Bulk Sintered MgB₂

Optimization of Carbon Encapsulated Boron Doping for High‐Performance Bulk Sintered MgB₂