title: Specific heat measurement of the layered nitride superconductor Li(x)ZrNCl.
abstract: Specific heat has been investigated in a layered nitride superconductor, Li(0.12)ZrNCl, with T(c)=12.7 K. The obtained data have shown a marked dichotomy: The specific heat jump at T(c) (DeltaC/gamma(n)T(c)=1.8) and the superconducting gap ratio (2Delta/k(B)T(c)=4.6-5.2) have indicated an intermediate to a strong coupling of electrons, while the upper limit of the electron-phonon coupling constant lambda has directly been estimated to be 0.22, which belongs to a weak coupling regime. Furthermore, the rapid increase of gamma as a function of magnetic field suggests that the present material has an anisotropic s wave gap.
authors.affiliation: Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Taguchi
authors.forename: M
authors.initials: M
authors.lastname: Hisakabe
authors.forename: Y
authors.initials: Y
authors.lastname: Iwasa