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Full-Text Articles in Engineering

The Synthesis Of Lamellar Nano Mgb2 Grains With Nanoimpurities, Flux Pinning Centers And Their Significantly Improved Critical Current Density, Zongqing Ma, Yongchang Liu, Qi Cai Jan 2012

The Synthesis Of Lamellar Nano Mgb2 Grains With Nanoimpurities, Flux Pinning Centers And Their Significantly Improved Critical Current Density, Zongqing Ma, Yongchang Liu, Qi Cai

Australian Institute for Innovative Materials - Papers

MgB2 superconductors with unique microstructures were rapidly fabricated at low temperatures, and exhibited significantly improved critical current density (Jc). According to the microstructure observations, the prepared samples consisted of lamellar nano MgB2 grains with many embedded nanoimpurities (about 10 nm). The formation of these lamellar nano MgB2 grains is associated with the presence of a local Mg-Cu liquid at sintering temperatures as low as 575°C. The ball milling treatment of the original powders also plays a positive role in the growth of lamellar grains. Based on an analysis of the relationship between resistivity and temperature, the lamellar nano MgB2 grains …


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 Jan 2012

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

Australian Institute for Innovative Materials - Papers

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 …


The Effects Of Annealing Temperature On The In-Field Jc And Surface Pinning In Silicone Oil Doped Mgb2 Bulks And Wires, M S. Hossain, A Motaman, O Cicek, H Agil, E Ertekin, A Gencer, Xiaolin Wang, S X. Dou Jan 2012

The Effects Of Annealing Temperature On The In-Field Jc And Surface Pinning In Silicone Oil Doped Mgb2 Bulks And Wires, M S. Hossain, A Motaman, O Cicek, H Agil, E Ertekin, A Gencer, Xiaolin Wang, S X. Dou

Australian Institute for Innovative Materials - Papers

No abstract provided.


Technical Aspects Of Cold High Pressure Densification (Chpd) On Long Lengths Of In Situ Mgb2 Wires With Enhanced Jc Values, R Flukiger, M S A Hossain, M Kulich, C Senatore Jan 2012

Technical Aspects Of Cold High Pressure Densification (Chpd) On Long Lengths Of In Situ Mgb2 Wires With Enhanced Jc Values, R Flukiger, M S A Hossain, M Kulich, C Senatore

Australian Institute for Innovative Materials - Papers

The technical aspects correlated with the observed enhancement of mass density and critical current density in the filaments of in situ MgB2 wires by means of the recently developed Cold High Pressure Densification (CHPD) are reviewed. The present analysis first summarizes the results obtained by means of a short sample prototype device with anvil lengths of 39 mm. Pressures well above 1 GPa were applied to short wires, causing Jc enhancements between a factor 1.5 and 2.3 at 4.2 K and 8 T. At 20 K, the enhancement is much stronger and reaches a factor 3 for binary and 5 …


The Effect Of Reduced Graphene Oxide Addition On The Superconductivity Of Mgb2, K S. B De Silva, S Gambhir, Xiaolin Wang, X Xu, W X. Li, David L. Officer, D Wexler, G G. Wallace, S. X. Dou Jan 2012

The Effect Of Reduced Graphene Oxide Addition On The Superconductivity Of Mgb2, K S. B De Silva, S Gambhir, Xiaolin Wang, X Xu, W X. Li, David L. Officer, D Wexler, G G. Wallace, S. X. Dou

Faculty of Engineering - Papers (Archive)

Reduced graphene oxide (rGO) and highly reduced chemically converted graphene (ICCO) samples were prepared under different processing condition! and were doped into MgBz by a diffusion process at 800 °C for 10 houn. It was demonstrated that a small addition rCCG can significantly improve the supcn;onducting properties of MgBz. Doping of M8B2 with 1 mol% of rCCG resulted in a Ie of 5.45 X lOS A cm-2 at 20 K in self-fields, which il nearly 32% improvement over that of the undopcd sample. This is a significant improvement as most carbon sources adversely affect the Ie performance: at the zero …


A Significant Improvement In The Superconducting Properties Of Mgb2 By Co-Doping With Graphene And Nano-Sic, K S B De Silva, X Xu, Xiaolin Wang, D Wexler, D Attard, F Xiang, S. X. Dou Jan 2012

A Significant Improvement In The Superconducting Properties Of Mgb2 By Co-Doping With Graphene And Nano-Sic, K S B De Silva, X Xu, Xiaolin Wang, D Wexler, D Attard, F Xiang, S. X. Dou

Faculty of Engineering - Papers (Archive)

The effects of graphene (G) and nanosilicon carbide (SiC) co-doping on the superconducting properties of MgB2 were studied using bulk samples. SiC remains one of the best dopants which can significantly improve the high field performance, while graphene is emerging as a new dopant for MgB2, which can improve the zero field critical current density (Jc). The superconducting properties characterized by Jc, the intergrain connectivity, and the critical fields were significantly improved by the use of both SiC and graphene as dopants.