Superconducting Ti15Zr15Nb35Ta35 High-Entropy Alloy With Intermediate Electron-Phonon Coupling

Abstract

The body-centered cubic (BCC) Ti 15 Zr 15 Nb 35 Ta 35 high-entropy alloy showed superconducting behavior at around 8 K. The electronic specific heat coefficient γ and the lattice specific heat coefficient β were determined to be γ = 9.3 ± 0.1 mJ/mol K 2 and β = 0.28 ± 0.01 mJ/mol K 4 , respectively. It was found that the electronic specific heat C es does follow the exponential behavior of the Bardeen-Cooper-Schrieffer (BCS) theory. Nevertheless, the specific heat jump (C/γ T c) at the superconducting transition temperature which was determined to be 1.71 deviates appreciably from that for a weak electron-phonon coupling BCS superconductor. Within the framework of the strong-coupled theory, our analysis suggests that theTi 15 Zr 15 Nb 35 Ta 35 HEA is an intermediate electron-phonon coupled BCS-type superconductor.

Synthesis of new high-entropy alloy-type Nb3 (Al, Sn, Ge, Ga, Si) superconductors

“…HEAs have recently attracted much attention in the fields of materials science and engineering because of their tunable properties as structural materials, such as excellent mechanical performance under extreme conditions [1,2]. As HEA superconductors, simple alloys with bcc, α-Mn, CsCl, and hcp crystal structures have mainly been studied so far [3][4][5][6][7][8][9][10][11][12][13][14]. Among these, Ta0.34Nb0.33Hf0.08Zr0.14Ti0.11 with a superconducting transition temperature (Tc) of 7.3 K, exhibits robustness in the superconducting state under extremely high pressures up to 190 GPa [4].…”

Bibliometric Mapping of Literature on High-Entropy/Multicomponent Alloys and Systematic Review of Emerging Applications

“…This material may potentially be useful for applications requiring extreme pressures. There are also other reports on the Ta-Nb-Hf-Zr-Ti system [139,140]. Similarly, Stolze et al [141] reported SC in the Zr-Nb-Mo-Re-Ru, Hf-Ta-W-Ir-Re, and Hf-Ta-W-Pt-Re systems.…”

“…Specifically, while T c increases linearly with VEC, it exhibits an inverse relationship with the lattice parameter. The phases in the reported SC HEA/MCAs can be broadly grouped into four, i.e., BCC [35,36,140], HCP [142,143], α-Mn [141], and CsCl [144].…”

Structure and Superconductivity of Tin-Containing HfTiZrSnM (M = Cu, Fe, Nb, Ni) Medium-Entropy and High-Entropy Alloys

“…According to the chemical/structural classification by Sun and Cava [28], the HEA superconductors are divided into four classes. Type-A HEA superconductors consist of the early transition metals with the bcc structure and small unit cells, with the representative examples Ta-Nb-Hf-Zr-Ti [22,[29][30][31][32][33] and Nb-Hf-Zr-Ti-V [34]. Type-B HEA superconductors are composed of the 4d and 5d transition metals (early and late), with the representatives (HfTaWIr) 1−x Re x , (ZrNb) 1−x (MoReRu) x and (HfTaWPt) 1−x Re x and x < 0.6.…”