Physics – Condensed Matter – Superconductivity
Scientific paper
2003-08-11
pp 111-130, "Superconductivity Research at the Leading Edge", Edited by P. S. Lewis, Nova Science Publishers, Inc., New York (
Physics
Condensed Matter
Superconductivity
27 pages, 9 pages, tentatively to appear in ''Horizons in Superconductivity'' by Nova Science Publishers, Inc
Scientific paper
The newly discovered superconductivity in MgCNi3, though with Tc<8 K lower than that of the celebrated MgB2, is probably even more interesting in its many puzzling physical properties. MgCNi3 has been theoretically speculated to be unstable towards ferromagnetism. However, there are numerous evidences from the specific heat C(T), Tunneling spectroscopy and NMR experiments indicating conventional s-wave superconductivity in MgCNi3. The Hall effect and the thermoelectric power experiments suggest that the carriers responsible for the transport properties are electrons, in obvious contrast to holes predicated by the band structure calculations. In this article, we report the results of C(T) experiments, upper critical field Hc2 measurements, and the pressure effects on MgCNi3. These experimental evidences clearly demonstrate that superconductivity in MgCNi3 is well explained within the conventional electron-phonon interaction scenario, at most with minor modifications from the magnetic interaction. The thermodynamic data C(T) is consistent with the conventional s-wave order parameter. Hc2 of all samples follows a universal WHH relation . Surprisingly, dTc/dP is positive which leaves room for further improvements in band structure calculations. There are other serious discrepancies between experiments and theory like in the transport properties and x-ray photoemission. The possible reconciliation within the two-band model and the consequent difficulties are discussed.
Lin Jian-Yu
Yang Hui-Di
No associations
LandOfFree
MgCNi3: a conventional and yet puzzling superconductor does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with MgCNi3: a conventional and yet puzzling superconductor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and MgCNi3: a conventional and yet puzzling superconductor will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-694413