Transport measurements of FeAs superconductors in the 150T single-turn magnet
- ETH Zurich (Switzerland)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
The large upper critical fields in the iron-pnictides well in excess of 100T at low temperatures render them prime candidates for high magnetic field applications. To reliably estimate such high upper critical fields, however, poses a significant experimental challenge. The multi-band nature of this material class has a profound impact on the Hc2(T) behavior due to the additional degrees of freedom arising from the difference between inter- and intra-band scattering, and the conventional means of extrapolating Hc2(0) from high-temperature measurements, such as the WHH formalism, must be considered with caution. Therefore establishing new experimental techniques to follow Hc2(T) to fields above 100T sheds light on the ultimate limits of applicability of pnictide superconductors as well as the temperature dependence of the internal scattering mechanisms that lead to the multi-band nature of superconductivity. Currently magnetic fields in excess of the 100T multi-shot magnet can only be created in destructive magnets. The single-turn system at NHMFL-PFF routinely delivers pulses of 150T and above. The short duration of the pulses (~4-8μs) and the increased noise levels compared to non-destructive pulse magnets are a serious experimental challenge. We have worked extensively on a combination of Focused Ion Beam micromachining and GHz stripline sample holder design to address these issues.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE; National Science Foundation (NSF)
- DOE Contract Number:
- AC52-06NA25396
- OSTI ID:
- 1114403
- Report Number(s):
- LA-UR-14-20073
- Country of Publication:
- United States
- Language:
- English
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