Speaker
carlo ferdeghini
(C)
Description
Among the various families of Fe-based superconductors, iron chalcogenides, although presenting a not particularly high transition temperature, show great advantages for potential applications in high field, albeit at liquid helium temperature .
The critical temperature in thin films can be increased by applying stress up to 21 K, but the stress can push the critical field up to more than 50 T (and the irreversibility field close to this value). Also critical currents up to 1 MA/cm2 in self-field at liquid helium temperature can be reached with a very weak dependence on the magnetic field. Interestingly the anisotropy depends on the mode of growth and the substrate used and the high values of critical current can be achieved without appreciable anisotropy.
In this work, STM and TEM techniques will be used to characterize pinning centers that are effective in different types of films.
It was shown that Fe-chalcogenide films can be deposited on technical oxide substrates. Interesting would be to develop metal technical polycrystalline substrates. Our preliminary measurements reported here, show that the critical current at the grain boundary is not severely depressed.
Author
carlo ferdeghini
(C)
Co-authors
Dr
Andrea Gerbi
(CNR-SPIN)
Dr
Emilio Bellingeri
(CNR-SPIN)
Prof.
Marina Putti
(CNR-SPIN)
Dr
Renato Buzio
(CNR-SPIN)
Shrikant Kawale
(CNR-SPIN)
Dr
Valeria Braccini
(CNR-SPIN)
