Enhancing Superconductivity of Lu5Rh6Sn18 by Atomic Disorder
A. Slebarski, M. Fijalkowski, M. M. Maska, J. Deniszczyk, P. Zajdel, Benjamin Trump, A. Yakovenko
For the number of skutterudite-related cage compounds such as cubic R3M4Sn13 (R = Ca or La, M = transition d-electron metal) or tetragonal Y5Rh6Sn18 we have previously reported the impact of various atomic defects in the crystal lattices on the normal-state and superconducting properties of these clathrates. In these quasi-skutterudites the nanoscale disorder and/or local inhomogeneity in composition lead to abnormal increase of the superconducting transition temperature Tc. Here we investigate the impact of atomic defects in the superconductors Lu5−δRhd6^Sn18 (tetragonal symmetry I41/acd). Our comprehensive investigations of electronic structure and thermodynamic and electrical transport properties documented a Tc increase of the more disordered sample δ = 0. The quality of each sample (δ = 0 and 0.4) was obtained by microanalysis and electron transmission microscopy observations. The band structure calculations show a hybridization pseudogap in the electronic bands of Lu5Rh6Sn18 at about 0.2 eV in respect to the Fermi level, εF. The ab initio calculations predict the scenario, that vacancies could shift this pseudogap towards εF, which is manifested by the Mott variable-range hopping behavior in the resistivity ρ ∼ T−1/4 of Lu4.6Rh6Sn18.
Physical Review B
Skutterudites, Superconductivity, Atomic Disorder, Chemical Tuning
, Fijalkowski, M.
, Maska, M.
, Deniszczyk, J.
, Zajdel, P.
, Trump, B.
and Yakovenko, A.
Enhancing Superconductivity of Lu<sub>5</sub>Rh<sub>6</sub>Sn<sub>18</sub> by Atomic Disorder, Physical Review B
(Accessed October 19, 2021)