Reaction-induced pore formation and superconductivity in in situ processed MgB2 superconductors

Kim, C.-J.; Jiao, Yi; Jun, Byung‐Hyuk; You, Byung Youn; Park, S.-D.; Choo, Kee Nam

doi:10.1016/j.physc.2014.04.006

Cited by 13 publications

(8 citation statements)

References 27 publications

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“…The apparent density of the heat treated pellets is less than 50% of the theoretical density(2.57 g/cm 3 [14]) of the MgB 2 . A density decrease after heat treatment was reported in an in-situ processed MgB 2 bulk superconductor, which used Mg and B powders as the starting materials [17,26]. The origin of the density decrease was confirmed as the pore formation by Mg melting and the fast Mg diffusion during the MgB 2 formation reaction.…”

Section: Resultsmentioning

confidence: 82%

“…During the in situ process for the formation of MgB 2 , the Mg powder with a melting temperature (m. p.) of 650℃ [15] melts and MgB 2 nucleates at the boron powders with an m. p. of 2200℃ [16]. As a result of the Mg melting and the fast diffusion of Mg toward the boron powder to form MgB 2 , the location of the Mg powders was converted into pores [17][18]. Consequently, the pore shape is similar to that of the Mg powder used.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of the size of Mg powder on the formation of MgB₂and the superconducting properties

Kim¹,

Jun²,

Park³

et al. 2016

Progress in Superconductivity and Cryogenics

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Section: Resultsmentioning

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Effects of the size of Mg powder on the formation of MgB₂and the superconducting properties

Kim¹,

Jun²,

Park³

et al. 2016

Progress in Superconductivity and Cryogenics

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“…The microstructures of undoped and doped samples look quite similar which consist of well-connected grains network along with porous structure which is typical for MgB 2 bulk [11,12]. The estimation of grain sizes from FESEM images was not possible, therefore, the crystallite sizes were calculated from XRD data and the values are given in Table 1.The pores are mainly developed by melting of Mg powders during sintering process [13].…”

Section: Resultsmentioning

confidence: 99%

A safe and cost-effective PMMA carbon source for MgB₂

Ranot¹,

Jang²,

Shinde³

et al. 2017

Progress in Superconductivity and Cryogenics

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Carbon is proven to be very effective in pinning the magnetic vortices and improving the superconducting performance of MgB 2 at high fields. In this work, we have used polymethyl methacrylate (PMMA) polymer as a safe and cost effective carbon source. The effects of molecular weight of PMMA on crystal structure, microstructure as well as on superconducting properties of MgB 2 were studied. X-ray diffraction analysis revealed that there is a noticeable shift in (100) and (110) Bragg reflections towards higher angles, while no shift was observed in (002) reflections for MgB 2 doped with different molecular weights of PMMA. This indicates that carbon could be substituted in the boron honeycomb layers without affecting the interlayer interactions. As compared to undoped MgB 2 , substantial enhancement in J c (H) properties was obtained for PMMA-doped MgB 2 samples both at 5 K and 20 K. The enhancement could be attributed to the effective carbon substitution for boron and the refinement of crystallite size by PMMA doping.

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“…Tampieri ve arkadaşları, sıcak presleme ile üretilen MgB2'nin fırınlanma sürecinden nasıl etkilendiğini incelediği çalışmalarında sıcaklık parametresi 1070 0 C ile 1190 0 C aralığında olan ticari MgB2'ler üzerinde araştırma yapmıştır [21]. Tel içinde yöntemi ile üretilen MgB2'de oluşacak gözeneklerin incelendiği bir çalışmada Kim ve arkadaşları MgB2 sentezini 600 0 C ile 900 0 C aralığında yapmışlardır [22]. 2009 yılında tel içinde yöntemi ile elde edilen MgB2 numunelerindeki gözenek şekillerinin incelendiği çalışmada Yi ve arkadaşları MgB2'yi 600 0 C ile 1000 0 C aralığında üretmişlerdir [23].…”

Section: Gi̇ri̇ş (Introduction)unclassified

CVD Yöntemi ile Karbon Katkılanmış Bor Kullanılarak Üretilen MgB2’nin Mikrosertlik Özelliklerinin İncelenmesi

Kaya

Çavdar

Koralay

2020

Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım Ve Teknoloji

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In this study, the CVD unit shown in Figura A in Ankara University Chemical Engineering Nanotechnology Laboratory was used. Amorphous boron powders were used as a source of acetylene hydrocarbon and carbon was added by CVD method for 90 minutes. Then, magnesium was added to the carbon doped amorphous boron powders at Gazi University Thermal Analysis Laboratory and mixed in an automatic mixer for 60 minutes. The powders were sintered under closed argon gas at determined temperatures and sample was obtained. Microhardness analyzes of the obtained samples were made. Figure A. CVD unit Purpose: In this study, it is aimed to improve the current mechanical properties of MgB2, which is used as a superconducting material, and to increase its usage area. Theory and Methods: MgB2, which shows superconductivity, has been produced with quite different production methods in order to improve its existing physical properties. One of them is to add different materials into the structure by adding. In this study, carbon was added to amorphous boron powders by CVD method. MgB2 was produced by mixing carbon-doped boron with magnesium classical solid-state reaction method. Vickers method was used for microhardness measurements. Results: While all of the samples show RISE behavior, contribution rate has been found to soften the material. Conclusion: As a result of the measurements, it was determined that the plane peak of MgB2 (1 0 1) in all samples was seen at 43,00 0 , the sharpest peak belonged to the C sample, the most successful approach in explaining the microhardness character of the samples was the Meyer Approach and IIC Approach.

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Reaction-induced pore formation and superconductivity in in situ processed MgB2 superconductors

Cited by 13 publications

References 27 publications

Effects of the size of Mg powder on the formation of MgB₂and the superconducting properties

Effects of the size of Mg powder on the formation of MgB₂and the superconducting properties

A safe and cost-effective PMMA carbon source for MgB₂

CVD Yöntemi ile Karbon Katkılanmış Bor Kullanılarak Üretilen MgB2’nin Mikrosertlik Özelliklerinin İncelenmesi

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Reaction-induced pore formation and superconductivity in in situ processed MgB2 superconductors

Cited by 13 publications

References 27 publications

Effects of the size of Mg powder on the formation of MgB2and the superconducting properties

Effects of the size of Mg powder on the formation of MgB2and the superconducting properties

A safe and cost-effective PMMA carbon source for MgB2

CVD Yöntemi ile Karbon Katkılanmış Bor Kullanılarak Üretilen MgB2’nin Mikrosertlik Özelliklerinin İncelenmesi

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Effects of the size of Mg powder on the formation of MgB₂and the superconducting properties

Effects of the size of Mg powder on the formation of MgB₂and the superconducting properties

A safe and cost-effective PMMA carbon source for MgB₂