Effects of ZrH2 doping and sintering temperature on the critical current density of MgB2 wires

2005 ◽  
Vol 426-431 ◽  
pp. 1244-1248
Author(s):  
H.L. Xu ◽  
Y. Feng ◽  
Z. Xu ◽  
C.S. Li ◽  
G. Yan ◽  
...  
2013 ◽  
Vol 484 ◽  
pp. 167-170 ◽  
Author(s):  
S.J. Ye ◽  
M. Song ◽  
A. Matsumoto ◽  
K. Togano ◽  
M. Takeguchi ◽  
...  

2010 ◽  
Vol 117 ◽  
pp. 63-68 ◽  
Author(s):  
Krishnankutty Vinod ◽  
Syamaprasad Upendran

The present study focuses on the preparation of good quality MgB2 superconductor in bulk, wire/tape forms and on the improvement of in-field critical current density [JC(H)]. MgB2 bulk superconductor was prepared by a simple Powder-In-Sealed-Tube (PIST) method and MgB2 wires and tapes were prepared by the Powder-In-Tube (PIT) method. A novel electrical self-heating method was introduced for the preparation of Fe sheathed MgB2 wires and tapes. Burned Rice Husk (BRH), an inexpensive natural material is found to be one of the best additives for enhancing the in-field critical current density of MgB2. By selecting suitable combinations of additives a significant enhancement of the critical current density by 1-2 orders of magnitude were achieved for fields > 5 T, at 5-15 K.


2014 ◽  
Vol 505 ◽  
pp. 39-43 ◽  
Author(s):  
Boris Brunner ◽  
Pavol Kováč ◽  
Michael Reissner ◽  
Imrich Hušek ◽  
Tibor Melišek ◽  
...  

1998 ◽  
Vol 13 (2) ◽  
pp. 261-268 ◽  
Author(s):  
J. P. Singh ◽  
N. Vasanthamohan

Silver-sheathed Bi–Pb–Sr–Ca–Cu–O (2223) superconducting tapes (with a starting composition of Bi1.8Pb0.4Sr2Ca1Cu2O8, calcium cuprate, and CuO) were fabricated by the powder-in-tube technique. The tapes were sintered at various temperatures to optimize the formation of Bi1.8Pb0.4Sr2Ca2Cu3O10 phase within the tape. The results show that sintering within the temperature range of 815–825 °C can produce tapes with high critical current density (Jc). The Jc of samples sintered at the higher temperature of 825 °C, where more liquid is present, depended markedly on the rate at which tapes were cooled from the sintering temperature; samples sintered at lower temperatures did not exhibit such a cooling-rate effect. The optimum combination of phase purity and microstructure that yielded an average transport Jc of ≥ 2.5 × 104 A/cm2 was obtained when the tapes were sintered at 825 °C for 150 h and cooled at a rate of 25 °C/h from the sintering temperature. Quenching studies indicate that the Bi-2223 phase becomes unstable below 700 °C during slow cooling. This result may have important implications for processing Bi–Sr–Ca–Cu–O tapes with high Jc. Addition of 15 vol.% Ag flakes to the monolithic core exerted no significant effect on Jc.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5152
Author(s):  
Daniel Gajda ◽  
Andrzej J. Zaleski ◽  
Andrzej J. Morawski ◽  
Malgorzata Małecka ◽  
Konstantin Nenkov ◽  
...  

Annealing undoped MgB2 wires under high isostatic pressure (HIP) increases transport critical current density (Jtc) by 10% at 4.2 K in range magnetic fields from 4 T to 12 T and significantly increases Jtc by 25% in range magnetic fields from 2 T to 4 T and does not increase Jtc above 4 T at 20 K. Further research shows that a large amount of 10% SiC admixture and thermal treatment under a high isostatic pressure of 1 GPa significantly increases the Jtc by 40% at 4.2 K in magnetic fields above 6 T and reduces Jtc by one order at 20 K in MgB2 wires. Additionally, our research showed that heat treatment under high isostatic pressure is more evident in wires with smaller diameters, as it greatly increases the density of MgB2 material and the number of connections between grains compared to MgB2 wires with larger diameters, but only during the Mg solid-state reaction. In addition, our study indicates that smaller wire diameters and high isostatic pressure do not lead to a higher density of MgB2 material and more connections between grains during the liquid-state Mg reaction.


2007 ◽  
Vol 457 (1-2) ◽  
pp. 47-54 ◽  
Author(s):  
G. Liang ◽  
M. Alessandrini ◽  
F. Yen ◽  
M. Hanna ◽  
H. Fang ◽  
...  

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