High-entropy silicide superconductors with W5Si3-type structure

We report the synthesis, crystal structure, and physical properties of two new high-entropy silicides (HESs), namely (Nb0.1Mo0.3W0.3Re0.2Ru0.1)(5)Si-3 and (Nb0.2Mo0.3W0.3Re0.1Ru0.1)(5)Si-3. Structural analysis indicates that both HESs consist of a (nearly) single tetragonal W5Si3-type phase (space group I4/mcm) with a disordered cation distribution. Electrical resistivity, magnetic susceptibility, and specific heat measurements show that (Nb0.1Mo0.3W0.3Re0.2Ru0.1)(5)Si-3 and (Nb0.2Mo0.3W0.3Re0.1Ru0.1)(5)Si-3 are weakly coupled bulk superconductors, which represent the first superconducting high-entropy nonoxide ceramics. In particular, these HESs have higher Tc values (3.2-3.3 K) compared with those of the binary counterparts and their B-c2(0)/T-c ratios are the largest among superconductors of the same structural type.

Automated summary

In this study, two new high-entropy silicides, (Nb0.1Mo0.3W0.3Re0.2Ru0.1)(5)Si-3 and (Nb0.2Mo0.3W0.3Re0.1Ru0.1)(5)Si-3, were synthesized and their crystal structure and physical properties were characterized. The results showed that both compounds were weakly coupled bulk superconductors with a tetragonal W5Si3-type phase and disordered cation distribution. Notably, these high-entropy silicides exhibited higher critical temperatures and the largest B-c2(0)/T-c ratios among superconductors with the same structural type.