Correlations among superconductivity, structural instability, and band filling in Nb1−xB2 at the critical point x≈0.2
R. J. Xiao, K. Q. Li, H. X. Yang, G. C. Che, H. R. Zhang, C. Ma, Z. X. Zhao, J. Q. Li
DOI 10.1103/PhysRevB.73.224516 · 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 performed an extensive investigation on the correlations among superconductivity, structural instability, and band filling in Nb1−xB2 materials. Structural measurements reveal that a notable phase transformation occurs at x≈0.2, corresponding to the Fermi level (EF) in the pseudogap with the minimum total density of states (DOS) as demonstrated by the first-principles calculations. Superconductivity in Nb1−xB2 generally becomes visible in the Nb-deficient materials with x⩾0.2. Electron energy-loss spectroscopy (EELS) measurements on B K edge directly demonstrated the presence of a chemical shift arising from the structural transformation. Our systematical experimental results in combination with theoretical analysis suggest that the emergence of hole states in the σ bands plays an important role for understanding the superconductivity and structural transition in Nb1−xB2.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| MgB2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 39 | Pressure not reported | unknown |
| NbB2.5 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | — | Pressure not reported | unknown |
| Nb1-xB2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 8 | 6 GPa | onset |
| Nb0.7B2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 8.1 | 6 GPa | onset |
Similar papers
Correlations among superconductivity, structural instability, and band filling in Nb1-xB2 at the critical point x=0.2
similarity 1.00R. J. Xiao et al. · 2006 · arXiv:cond-mat/0603706
Source status unknown — claims are unverified
Electronic and dynamical properties of the MgB2 surface: Implications for the superconducting properties
similarity 0.96G. Profeta et al.
Source status unknown — claims are unverified
Theory of the critical current in two-band superconductors with application to MgB2
similarity 0.96E. J. Nicol & J. P. Carbotte
Source status unknown — claims are unverified
High magnetic field superconductivity in a two-band superconductor
similarity 0.96Tancredi Salamone et al.
Source status unknown — claims are unverified
Thermodynamic stabilities of ternary metal borides: An ab initio guide for synthesizing layered superconductors
similarity 0.96Aleksey N. Kolmogorov et al.
Source status unknown — claims are unverified
Conventional high-temperature superconductivity in σ-band driven metallized two-dimensional metal borocarbides
similarity 0.96Yiming Zhang et al.
Source status unknown — claims are unverified