Superconductivity in Nb₅Ir_3−xPt_xO

Abstract

We have investigated the superconducting critical temperature T c of solid solution Nb 5 Ir 3−x Pt x O with the Ti 5 Ga 4-type structure. The both end-members of Nb 5 Ir 3 O and Nb 5 Pt 3 O are reported to be superconductors with T c of 10.5 K and 3.8 K, respectively. Particularly Nb 5 Ir 3 O is considered as a two-gap superconductor. The entire series of alloy hold the Ti 5 Ga 4-type structure and show the linear x dependence of lattice parameters. On the other hand, a nonlinear T c vs x plot was obtained, suggesting that T c is not determined by only lattice parameters. The experimental result is discussed based on the Matthias rule and compared with those of the other two-gap superconductors such as MgB 2 , Mo 8 Ga 41 and Nb 3 Sn.

Group-9 Transition-Metal Suboxides Adopting the Filled-Ti2Ni Structure: A Class of Superconductors Exhibiting Exceptionally High Upper Critical Fields

“…14 Less commonly, electron-acceptor atoms, or anions, are doped into structural void positions to achieve superconductivity. 15,16 A recent example for the enhancement of superconductivity in such a material is Nb 5 Ir 3 O with a critical temperature of T c ≈ 10.5 K. 15 Here, oxygen O 2− anions are occupying trigonal antiprismatic channels in the Mn 5 Si 3 -type host structure.…”

“…While there are a wide range of superconducting applications that would strongly benefit from new materials, state-of-the-art computational methods are struggling to predict the highly complex collective electronic state of superconductors. , Hence, for the search of new and improved superconducting materials, one has to rely on utilizing chemical and physical design principles, such as looking for new materials with structural features from known superconductors and electron counting. − One chemical approach to this has been the exploration of materials in which the electronic properties can be tuned precisely by the addition of dopants between layers or into void positions. − For this purpose, electron-donor atoms, or cations, are most commonly incorporated into the structure, as, for example, in Cu x TiSe 2 , where superconductivity with a critical temperature of T c ≈ 4 K was discovered via the intercalation of copper between the TiSe 2 layers . Less commonly, electron-acceptor atoms, or anions, are doped into structural void positions to achieve superconductivity. , A recent example for the enhancement of superconductivity in such a material is Nb 5 Ir 3 O with a critical temperature of T c ≈ 10.5 K . Here, oxygen O 2– anions are occupying trigonal antiprismatic channels in the Mn 5 Si 3 -type host structure.…”

Cutting Edge of High-Entropy Alloy Superconductors from the Perspective of Materials Research

“…Several superconductors with a hexagonal Mn5Si3-type-or its ordered derivative Ti5Ga4-type-structure have been reported [50][51][52][53][54][55][56]. Furthermore, each crystal structure type possesses rich intermetallic compounds [57,58]. The selected XRD patterns are given in Figure 11…”

Materials Research on High-Entropy Alloy Superconductors

“…Recently, several superconductors with the Mn 5 Si 3type-or its ordered derivative Ti 5 Ga 4 -type-structure have been found and attract much attention [38][39][40][41][42][43][44]. Besides, many intermetallic compounds are crystallizing into these crystal structures [45,46]. Figure 1(b) shows the crystal structure of the Mn 5 Si 3 -type compound represented by M 5 X 3 .…”