Seminarium Oddziału Badań Magnetyków
Microsoft Teams
Superconductivity enhanced by atomic disorder
prof. dr hab. Andrzej Ślebarski
Oddział Badań Magnetyków, INTiBS PAN
Seminarium odbędzie się zdalnie w aplikacji Microsoft Teams. W celu wzięcia udziału w wydarzeniu należy dołączyć do zespołu Seminarium OBM.Można do niego dołączyć na stałe przy użyciu kodu dostępu ol7omod (dotyczy to osób posiadających konto w domenie intibs.pl, pozostałe osoby proszę o kontakt z prof. dr. hab. Piotrem Wiśniewskim ()).
Streszczenie:
We investigated the effect of enhancement of superconducting transition temperature Tc by nonmagnetic atom disorder in the series of filled skutterudite-related compounds (La3M4Sn13, Ca3Rh4Sn13, Y5Rh6Sn18, Lu5Rh6Sn18; M= Co, Ru, Rh), where the atomic disorder is generated by various defects or doping. We have shown that the disorder on the coherence length scale ξ in these nonmagnetic quasi‑skutterudite superconductors additionally generates a non-homogeneous, “high‑temperature” superconducting phase with Tc* > Tc (dilute disorder scenario), while the strong fluctuations of stoichiometry due to increasing doping can rapidly increase the superconducting transition temperature of the sample even to the value of Tc* ~ Tc (dense disorder leading to strong inhomogeneity). This phenomenon seems to be characteristic of high-temperature superconductors superconducting SCESs and superconducting heavy fermions, and recently have received renewed attention. We documented experimentally the stronger lattice stiffening of the inhomogeneous superconducting phase Tc* in respect to the bulk Tc one and propose a phenomenological model that explains the Tc* > Tc behavior in the series of nonmagnetic skutterudite-related compounds.
