Physical Sciences and Mathematics | Open Access Articles

Power-Law Relationship Between Critical Current Density, Microstructure, And The N-Value In Mgb2 Superconductor Wires, Ashkan Motaman, Shaon Barua, Dipak Patel, Minoru Maeda, Kookchae Cheong, Jung Ho Kim, S X. Dou, Md Shahriar Al Hossain

Shi Xue Dou

Dissipation-free MgB2 superconducting wires are valuable in terms of practical applications. Herein, we have found a strong correlation between critical current density (J c ) and the n-value extracted from the electric field versus current density characteristic. The power-law relationship (m) between the J c and the n-value, n∝Jmc , represents a critical index which is strongly dependent on operating temperatures.

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Formation Of Magnesium Diboride-Based Materials With High Critical Currents And Mechanical Characteristics By High-Pressure Synthesis, Tetiana Prikhna, W. Gawalek, Ya M. Savchuk, N. V. Sergienko, V. E. Moshchil, M. Wendt, M. Zeisberger, T. Habisreuther, V. B. Sverdun, S X. Dou, S. N. Dub, V. S. Melnikov, Ch Schmidt, J. Dellith, P. A. Nagorny

Shi Xue Dou

The developed method of high-pressure synthesis (HPS) allows producing nanostructural highly dense material based on MGB2, which possesses the highest superconducting and mechanical characteristics among the known world analogues, in the form of blocks that are suitable for application in SC electromotors and pumps. Additions of Zr can increase critical current density (jc) of synthesized at 2 GPa and 750-800 °C MGB2 in the same manner as additions of Ta or Ti, i.e. due to the absorption of impurity hydrogen forming the ZrH2. The formation of ZrB2 phase at higher synthesis temperatures (about 950 °C) in HPS MGB2 does not …

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Critical Phenomena And Estimation Of The Spontaneous Magnetization By A Magnetic Entropy Analysis In Mn0.96nb0.04coge Alloy, Jyotish C. Debnath, A M. Strydom, P Shamba, Jianli Wang, S X. Dou

Shi Xue Dou

Magnetic and magnetocaloric properties of the alloy Mn0.96Nb0.04CoGe have been investigated.

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Investigation Of The Critical Behavior In Mn0.94nb 0.06coge Alloy By Using The Field Dependence Of Magnetic Entropy Change, J C. Debnath, P Shamba, A M. Strydom, Jianli Wang, S X. Dou

Shi Xue Dou

The critical behaviour of Mn0.94Nb0.06CoGe alloy around the paramagnetic-ferromagnetic phase transition was studied based on the field dependence on magnetic entropy change. By using the obtained exponents, the modified Arrott plot is consistent with that by using conventional method. These critical exponents are confirmed by the Widom scaling relation. Based on these critical exponents, the magnetization, field and temperature data around Tc collapse into two curves obeying the single scaling equation MðH; e)¼ebf6(H/ebþc). The calculated critical exponents not only obey the scaling theory but also anastomose the deduced results from the Kouvel-Fisher method [J. S. Kouvel and M. E. Fisher, …

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Microscopic Role Of Carbon On Mgb2 Wire For Critical Current Density Comparable To Nbti, Jung Ho Kim, Sangjun Oh, Yoon-Uk Heo, Satoshi Hata, Hiroaki Kumakura, Akiyoshi Matsumoto, Masatoshi Mitsuhara, Seyong Choi, Yusuke Shimada, Minoru Maeda, Judith Macmanus-Driscoll, S X. Dou

Shi Xue Dou

Increasing dissipation-free supercurrent has been the primary issue for practical application of superconducting wires. For magnesium diboride, MgB2, carbon is known to be the most effective dopant to enhance high-field properties. However, the critical role of carbon remains elusive, and also low-field critical current density has not been improved. Here, we have undertaken malic acid doping of MgB2 and find that the microscopic origin for the enhancement of high-field properties is due to boron vacancies and associated stacking faults, as observed by high-resolution transmission electron microscopy and electron energy loss spectroscopy. The carbon from the malic acid almost uniformly encapsulates …

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Silicon Oil: A Cheap Liquid Additive For Enhancing In-Field Critical Current Density In Mgb2, Xiaolin Wang, Zhenxiang Cheng, S X. Dou

Shi Xue Dou

In this work, the authors report on significant flux pinning enhancement in MgB2 that has been easily obtained using a liquid additive, silicon oil. MgB2 bulk samples with 0 up to 30 wt % silicon oil added were prepared by an in situ reaction. Results showed that the Si and C released from the decomposition of the silicon oil formed Mg2Si and substituted into B sites, respectively. Increasing the amount of the Si oil up to 15 wt % has resulted in the reduction of the lattice parameters, as well as Tc and R(300 K)/R(Tc) values, accompanied by a significant …

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Full-Text Articles in Physical Sciences and Mathematics

Power-Law Relationship Between Critical Current Density, Microstructure, And The N-Value In Mgb2 Superconductor Wires, Ashkan Motaman, Shaon Barua, Dipak Patel, Minoru Maeda, Kookchae Cheong, Jung Ho Kim, S X. Dou, Md Shahriar Al Hossain

Shi Xue Dou

Shi Xue Dou

Critical Phenomena And Estimation Of The Spontaneous Magnetization By A Magnetic Entropy Analysis In Mn0.96nb0.04coge Alloy, Jyotish C. Debnath, A M. Strydom, P Shamba, Jianli Wang, S X. Dou

Shi Xue Dou

Investigation Of The Critical Behavior In Mn0.94nb 0.06coge Alloy By Using The Field Dependence Of Magnetic Entropy Change, J C. Debnath, P Shamba, A M. Strydom, Jianli Wang, S X. Dou

Shi Xue Dou

Microscopic Role Of Carbon On Mgb2 Wire For Critical Current Density Comparable To Nbti, Jung Ho Kim, Sangjun Oh, Yoon-Uk Heo, Satoshi Hata, Hiroaki Kumakura, Akiyoshi Matsumoto, Masatoshi Mitsuhara, Seyong Choi, Yusuke Shimada, Minoru Maeda, Judith Macmanus-Driscoll, S X. Dou

Shi Xue Dou

Silicon Oil: A Cheap Liquid Additive For Enhancing In-Field Critical Current Density In Mgb2, Xiaolin Wang, Zhenxiang Cheng, S X. Dou

Shi Xue Dou