Nonmonotonic superconducting transition temperature and large bulk modulus in the alloy superconductor Nb4Rh2C1−δ
Lifen Shi, Keyuan Ma, Binbin Ruan, Ningning Wang, Jun Hou, Pengfei Shan, Pengtao Yang, Jianping Sun, Genfu Chen, Zhian Ren, Fabian O. von Rohr, Bosen Wang, Jinguang Cheng
DOI 10.1103/PhysRevB.110.214520 · Physical Review B
Active bibliographic source — not scientific approval
Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.
Abstract
We revised normal-state and superconducting properties of an alloy superconductor Nb4Rh2C1−δ through electrical transport, magnetic susceptibility, and specific heat. Our results reveal that it is a Pauli paramagnetic bad metal, a strongly coupled superconductor with specific heat jump ΔCe/γnTc∼1.65 and double s-wave gap symmetry. The evolution of superconducting transition temperature Tc was investigated by high-pressure electrical transport. It was found that Tc exhibits a nonmonotonic pressure dependence with a maximum Tcmax∼11 K, which is a record for the η-carbide alloy superconductors. Zero-temperature upper critical field Bc2(0) reduces smoothly from beyond to below the Pauli limit in 40–50 GPa. In situ synchrotron x-ray diffraction reveals a relatively large bulk modulus B0 ∼ 278.6 GPa in comparison with other alloy superconductors, which can explain the small-pressure coefficient dTc/dP ∼ −0.045 K/GPa above 20 GPa. The observations of high Tc and large B0 make Nb4Rh2C1−δ a promising superhard alloy superconductor. The pressure evolution of Bc2(0) is discussed in terms of Fermi surface reconstructions and the ratio of superconducting coherence length and electron mean free path of polycrystalline superconductors.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| Nb4Rh2C1-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 9.75 | Pressure unresolved | onset |
| Nb4Rh2C1-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 9.6 | Pressure unresolved | zero_resistance |
| Nb4Rh2C1-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 9.75 | Pressure unresolved | onset |
| Nb4Rh2C1-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 11 | 19.1 GPa | onset |
| NbTi Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 9.6 | Pressure not reported | unknown |
| Nb3Sn Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 18.1 | Pressure not reported | unknown |
Similar papers
Pressure dependence of the superconducting transition temperature in single-crystal NbBx (x near 2) with Tc=9.4 K
similarity 0.93J. E. Schirber et al.
Source status unknown — claims are unverified
Outer layers determine the parallel critical field of a superconducting multilayer
similarity 0.91W. Maj & J. Aarts
Source status unknown — claims are unverified
Electronic fine structure in the nickel carbide superconductor Th2NiC2
similarity 0.91Y. Quan & W. E. Pickett
Source status unknown — claims are unverified
Pressure effects and specific heat in superconducting HoNi2B2C
similarity 0.91S. A. Carter et al.
Source status unknown — claims are unverified
Unconventional Superconductivity in Electron-Doped Layered Li0.48(THF)yHfNCl
similarity 0.91H. Tou et al.
Source status unknown — claims are unverified
Superconductivity with High Upper Critical Field in the Cubic Centrosymmetric -Carbide NbRhC
similarity 0.91KeYuan Ma et al. · 2021 · arXiv:2106.13063
Source status unknown — claims are unverified