title: Interlayer-spacing dependence of Tc in LixMyHfNCl (M: molecule) superconductors.
abstract: We have systematically investigated the global phase diagram for Li{x}M{y}HfNCl (M: molecule), demonstrating the independent controllability of carrier density x and interlayer spacing d. In LixHfNCl, the superconducting phase with almost constant T{c} of 20 K prevails for 0.15<or<or.50. Accompanied by an increase in d upon the cointercalation, an enhancement of T{c} up to 30% was observed with its x independence preserved. This result indicates that pairing interaction strongly depends on the Fermi surface warping along the k{z} direction, implying the relevance of charge and/or spin fluctuation.
authors.affiliation: Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takano
authors.forename: T
authors.initials: T
authors.lastname: Kishiume
authors.forename: Y
authors.initials: Y
authors.lastname: Taguchi
authors.forename: Y
authors.initials: Y
authors.lastname: Iwasa