We report on the development of multifilamentary Nb3Sn superconductors by a versatile powder-in-tube technique (PIT) that demonstrates a simple pathway to a strand with a higher density of flux-pinning sites that has the potential to increase critical current density beyond present levels. The approach uses internal oxidation of Zr-alloyed Nb tubes to produce Zr oxide particles within the Nb3Sn layer that act as a dispersion of artificial pinning centres (APCs). In this design, SnO2 powder is mixed with Cu5Sn4 powder within the PIT core that supplies the Sn for the A15 reaction with Nb1Zr filament tubes. Initial results show an average grain size of ~38 nm in the A15 layer, compared to the 90–130 nm of typical APC-free high-Jc strands made by conventional PIT or Internal Sn processing. Furthermore, there is a shift in the peak of the pinning force curve from H/H irr of ~0.2 to ~0.3 and the pinning force curves can be deconvoluted into grain boundary and point-pinning components, the point-pinning contribution dominating for the APC Nb-1wt%Zr strands.
Motowidlo, Leszek R., et al. "An intermetallic powder-in-tube approach to increased flux-pinning in Nb<sub>3</sub>Sn by internal oxidation of Zr." Superconductor Science and Technology, vol. 31, no. 1, Nov. 2017. https://doi.org/10.1088/1361-6668/aa980f
Motowidlo, Leszek R., Lee, P. J., Tarantini, C., Balachandran, S., Ghosh, A. K., & Larbalestier, D. C. (2017). An intermetallic powder-in-tube approach to increased flux-pinning in Nb<sub>3</sub>Sn by internal oxidation of Zr. Superconductor Science and Technology, 31(1). https://doi.org/10.1088/1361-6668/aa980f
Motowidlo, Leszek R., Lee, P. J., Tarantini, C., et al., "An intermetallic powder-in-tube approach to increased flux-pinning in Nb<sub>3</sub>Sn by internal oxidation of Zr," Superconductor Science and Technology 31, no. 1 (2017), https://doi.org/10.1088/1361-6668/aa980f
@article{osti_1410559,
author = {Motowidlo, Leszek R. and Lee, P. J. and Tarantini, C. and Balachandran, S. and Ghosh, A. K. and Larbalestier, D. C.},
title = {An intermetallic powder-in-tube approach to increased flux-pinning in Nb<sub>3</sub>Sn by internal oxidation of Zr},
annote = {We report on the development of multifilamentary Nb3Sn superconductors by a versatile powder-in-tube technique (PIT) that demonstrates a simple pathway to a strand with a higher density of flux-pinning sites that has the potential to increase critical current density beyond present levels. The approach uses internal oxidation of Zr-alloyed Nb tubes to produce Zr oxide particles within the Nb3Sn layer that act as a dispersion of artificial pinning centres (APCs). In this design, SnO2 powder is mixed with Cu5Sn4 powder within the PIT core that supplies the Sn for the A15 reaction with Nb1Zr filament tubes. Initial results show an average grain size of ~38 nm in the A15 layer, compared to the 90–130 nm of typical APC-free high-Jc strands made by conventional PIT or Internal Sn processing. Furthermore, there is a shift in the peak of the pinning force curve from H/H irr of ~0.2 to ~0.3 and the pinning force curves can be deconvoluted into grain boundary and point-pinning components, the point-pinning contribution dominating for the APC Nb-1wt%Zr strands.},
doi = {10.1088/1361-6668/aa980f},
url = {https://www.osti.gov/biblio/1410559},
journal = {Superconductor Science and Technology},
issn = {ISSN 0953-2048},
number = {1},
volume = {31},
place = {United States},
publisher = {IOP Publishing},
year = {2017},
month = {11}}
ADVANCES IN CRYOGENIC ENGINEERING: Proceedings of the International Cryogenic Materials Conference - ICMC, AIP Conference Proceedingshttps://doi.org/10.1063/1.1472643
Motowidlo, L. R.; Ozeryansky, G. M.; Balachandran, U. (Balu)
ADVANCES IN CRYOGENIC ENGINEERING MATERIALS: Transactions of the International Cryogenic Materials Conference - ICMC, Vol. 54, AIP Conference Proceedingshttps://doi.org/10.1063/1.2900355