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Hot pressing to enhance the transport Jc of Sr0.6K0.4Fe2As2 superconducting tapes.

Lin H, Yao C, Zhang X, Dong C, Zhang H, Wang D, Zhang Q, Ma Y, Awaji S, Watanabe K, Tian H, Li J - Sci Rep (2014)

Bottom Line: High-performance Sr0.6K0.4Fe2As2 (Sr-122) tapes have been successfully fabricated using hot pressing (HP) process.The effect of HP temperatures (850-925°C) on the c-axis texture, resistivity, Vickers micro-hardness, microstructure and critical current properties has been systematically studied.Our results clearly strengthen the position of iron-pnictide conductors as a competitor to the conventional and MgB2 superconductors for high field applications.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Applied Superconductivity, Institute of Electrical Engineering, Chinese Academy of Sciences, PO Box 2703, Beijing 100190, China.

ABSTRACT
High-performance Sr0.6K0.4Fe2As2 (Sr-122) tapes have been successfully fabricated using hot pressing (HP) process. The effect of HP temperatures (850-925°C) on the c-axis texture, resistivity, Vickers micro-hardness, microstructure and critical current properties has been systematically studied. Taking advantage of high degree of c-axis texture, well grain connectivity and large concentration of strong-pinning defects, we are able to obtain an excellent Jc of 1.2 × 10(5) A/cm(2) at 4.2 K and 10 T for Sr-122 tapes. More importantly, the field dependence of Jc turns out to be very weak, such that in 14 T the Jc still remains ~ 1.0 × 10(5) A/cm(2). These Jc values are the highest ever reported so far for iron-pnictide wires and tapes, achieving the level desired for practical applications. Our results clearly strengthen the position of iron-pnictide conductors as a competitor to the conventional and MgB2 superconductors for high field applications.

No MeSH data available.


Related in: MedlinePlus

Bulk XRD patterns for the superconducting cores of the hot-pressed Sr-122 tapes prepared at 850, 875, 900 and 925°C.As a reference, the data for randomly orientated powder is also included. The peaks of Sr0.6K0.4Fe2As2 phase are indexed, while the peaks of Ag and AgSrAs phases are also marked. The Ag peaks are contributed from the Ag sheath.
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f1: Bulk XRD patterns for the superconducting cores of the hot-pressed Sr-122 tapes prepared at 850, 875, 900 and 925°C.As a reference, the data for randomly orientated powder is also included. The peaks of Sr0.6K0.4Fe2As2 phase are indexed, while the peaks of Ag and AgSrAs phases are also marked. The Ag peaks are contributed from the Ag sheath.

Mentions: The bulk XRD patterns for the hot-pressed Sr-122 samples with different HP temperatures are shown in Fig. 1. For comparison, the data for randomly orientated powder is also included. It can be seen that all tape samples exhibit a well developed Sr-122 phase, with a small amount of AgSrAs phase. On the other hand, compared with randomly orientated powder, the relative intensity of the (00l) peaks with respect to that of the (103) peak is strongly enhanced for our HP samples. The strong c-axis orientation of Sr-122 grains is achieved after hot pressing. Fig. 2 exhibits the temperature dependence of the resistivity for HP tapes. Similar high onset temperature Tc ~ 36.2 K and small transition width ~0.7 K are observed for all Sr-122 samples. In addition, the electrical resistivity curves display the characteristic temperature dependence of 122-type pnictides with a high ratio of room-temperature and normal-sate resistivity151617. The resistivity measurement demonstrates good quality of our HP tapes, which encourages a further detailed investigation on transport Jc-B properties and microstructure.


Hot pressing to enhance the transport Jc of Sr0.6K0.4Fe2As2 superconducting tapes.

Lin H, Yao C, Zhang X, Dong C, Zhang H, Wang D, Zhang Q, Ma Y, Awaji S, Watanabe K, Tian H, Li J - Sci Rep (2014)

Bulk XRD patterns for the superconducting cores of the hot-pressed Sr-122 tapes prepared at 850, 875, 900 and 925°C.As a reference, the data for randomly orientated powder is also included. The peaks of Sr0.6K0.4Fe2As2 phase are indexed, while the peaks of Ag and AgSrAs phases are also marked. The Ag peaks are contributed from the Ag sheath.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4221786&req=5

f1: Bulk XRD patterns for the superconducting cores of the hot-pressed Sr-122 tapes prepared at 850, 875, 900 and 925°C.As a reference, the data for randomly orientated powder is also included. The peaks of Sr0.6K0.4Fe2As2 phase are indexed, while the peaks of Ag and AgSrAs phases are also marked. The Ag peaks are contributed from the Ag sheath.
Mentions: The bulk XRD patterns for the hot-pressed Sr-122 samples with different HP temperatures are shown in Fig. 1. For comparison, the data for randomly orientated powder is also included. It can be seen that all tape samples exhibit a well developed Sr-122 phase, with a small amount of AgSrAs phase. On the other hand, compared with randomly orientated powder, the relative intensity of the (00l) peaks with respect to that of the (103) peak is strongly enhanced for our HP samples. The strong c-axis orientation of Sr-122 grains is achieved after hot pressing. Fig. 2 exhibits the temperature dependence of the resistivity for HP tapes. Similar high onset temperature Tc ~ 36.2 K and small transition width ~0.7 K are observed for all Sr-122 samples. In addition, the electrical resistivity curves display the characteristic temperature dependence of 122-type pnictides with a high ratio of room-temperature and normal-sate resistivity151617. The resistivity measurement demonstrates good quality of our HP tapes, which encourages a further detailed investigation on transport Jc-B properties and microstructure.

Bottom Line: High-performance Sr0.6K0.4Fe2As2 (Sr-122) tapes have been successfully fabricated using hot pressing (HP) process.The effect of HP temperatures (850-925°C) on the c-axis texture, resistivity, Vickers micro-hardness, microstructure and critical current properties has been systematically studied.Our results clearly strengthen the position of iron-pnictide conductors as a competitor to the conventional and MgB2 superconductors for high field applications.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Applied Superconductivity, Institute of Electrical Engineering, Chinese Academy of Sciences, PO Box 2703, Beijing 100190, China.

ABSTRACT
High-performance Sr0.6K0.4Fe2As2 (Sr-122) tapes have been successfully fabricated using hot pressing (HP) process. The effect of HP temperatures (850-925°C) on the c-axis texture, resistivity, Vickers micro-hardness, microstructure and critical current properties has been systematically studied. Taking advantage of high degree of c-axis texture, well grain connectivity and large concentration of strong-pinning defects, we are able to obtain an excellent Jc of 1.2 × 10(5) A/cm(2) at 4.2 K and 10 T for Sr-122 tapes. More importantly, the field dependence of Jc turns out to be very weak, such that in 14 T the Jc still remains ~ 1.0 × 10(5) A/cm(2). These Jc values are the highest ever reported so far for iron-pnictide wires and tapes, achieving the level desired for practical applications. Our results clearly strengthen the position of iron-pnictide conductors as a competitor to the conventional and MgB2 superconductors for high field applications.

No MeSH data available.


Related in: MedlinePlus