Superconducting energy gap in MgCNi3 single crystals: Point-contact spectroscopy and specific-heat measurements
Z. Pribulová, J. Kačmarčík, C. Marcenat, P. Szabó, T. Klein, A. Demuer, P. Rodiere, D. J. Jang, H. S. Lee, H. G. Lee, S.-I. Lee, P. Samuely
DOI 10.1103/PhysRevB.83.104511 · 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
Specific heat has been measured down to 600 mK and up to 8 T by highly sensitive ac microcalorimetry on MgCNi3 single crystals with Tc≈ 7 K. Exponential decay of the electronic specific heat at low temperatures proved that a superconducting energy gap is fully open on the whole Fermi surface, in agreement with our previous magnetic penetration depth measurements on the same crystals. The specific-heat data analysis shows consistently the strong-coupling strength 2Δ/kBTc≈4. This scenario is supported by the direct measurements of the gap via the point-contact spectroscopy. Moreover, the spectroscopy measurements show a decrease in the critical temperature at the sample surface, which accounts for the observed differences of the superfluid density deduced from the measurements by different techniques.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| MgCNi3 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 6.85 | Pressure not reported | midpoint |
Similar papers
Experimental determination of superconducting parameters for the intermetallic perovskite superconductor MgCNi3
similarity 0.96Z. Q. Mao et al.
Source status unknown — claims are unverified
s-wave superconductivity probed by measuring magnetic penetration depth and lower critical field of MgCNi3 single crystals
similarity 0.96P. Diener et al.
Source status unknown — claims are unverified
BCS-like superconductivity in MgCNi3
similarity 0.96J.-Y. Lin et al.
Source status unknown — claims are unverified
Competition between BCS superconductivity and ferromagnetic spin fluctuations in MgCNi3
similarity 0.95L. Shan et al.
Source status unknown — claims are unverified
Phonon dispersions and anomalies of MgCNi3 single-crystal superconductors determined by inelastic x-ray scattering
similarity 0.95Hawoong Hong et al.
Source status unknown — claims are unverified
Influence of carbon concentration on the superconductivity in MgCxNi3
similarity 0.94L. Shan et al.
Source status unknown — claims are unverified