Enhancing Superconductivity of Lu5Rh6Sn18 by Atomic Disorder

Published

April 19, 2021

Author(s)

A. Slebarski, M. Fijalkowski, M. M. Maska, J. Deniszczyk, P. Zajdel, Benjamin Trump, A. Yakovenko

Abstract

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 T_c. Here we investigate the impact of atomic defects in the superconductors Lu_5−δRhd6^Sn₁₈ (tetragonal symmetry I4₁/acd). Our comprehensive investigations of electronic structure and thermodynamic and electrical transport properties documented a T_c 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, ε_F. The ab initio calculations predict the scenario, that vacancies could shift this pseudogap towards ε_F, which is manifested by the Mott variable-range hopping behavior in the resistivity ρ ∼ T^−1/4 of Lu_4.6Rh₆Sn₁₈.

Citation

Physical Review B

Volume

103

Issue

15

Pub Type

Journals

Keywords

Skutterudites, Superconductivity, Atomic Disorder, Chemical Tuning

Citation

Slebarski, A. , Fijalkowski, M. , Maska, M. , Deniszczyk, J. , Zajdel, P. , Trump, B. and Yakovenko, A. (2021), Enhancing Superconductivity of Lu₅Rh₆Sn₁₈ by Atomic Disorder, Physical Review B (Accessed July 2, 2024)