2004/04/30 by L. Shan, Z. Y. Liu, Ziyi Liu +4 · 1 citation
Materials Science · Physics and Astronomy · #Magnetic and transport properties of perovskites and related materials #Superconductivity in MgB2 and Alloys #Thermal Expansion and Ionic Conductivity #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.71.144516
published as PRB 71, 144516 (2005) · To appear in Physical Review B, 6 pages, 7 figures
arxiv created 2005/02/24 · openalex publication_date 2005/04/29 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The low temperature specific heat of the superconductor MgCNi3 and a nonsuperconductor MgC0.85Ni3 is investigated in detail. An additional contribution is observed from the data of MgCNi3 but absent in MgC0.85Ni3, which is demonstrated to be insensitive to the applied magnetic field even up to 12\phantom\rule0.3em0exT. A detailed discussion on its origin is then presented. By subtracting this additional contribution, the zero field specific heat of MgCNi3 can be well described by the BCS theory with the gap ratio (\ensuremathΔ∕kBTc) determined by the previous tunneling measurements. The conventional s-wave pairing state is further proved by the magnetic field dependence of the specific heat at low temperatures and the behavior of the upper critical field.