title: Uniaxial pressure effects on CeIrIn5 and CeCoIn5 studied by low-temperature thermal expansion.
abstract: We report low-temperature thermal expansion measurements on the tetragonal heavy-fermion superconductors CeMIn5 (M=Ir,Co) in magnetic fields up to 8 T which allow for the analysis of the uniaxial pressure effects on both normal-state and superconducting properties. Our study reveals that T(c) is strongly affected by at least two factors, the lattice anisotropy and the 4f-conduction-electron hybridization strength which is most sensitive to c-axis lattice distortions. Non-Fermi-liquid behavior caused by quantum-critical fluctuations is observed for both systems, most pronounced for CeCoIn5.
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Oeschler
authors.forename: P
authors.initials: P
authors.lastname: Gegenwart
authors.forename: M
authors.initials: M
authors.lastname: Lang
authors.forename: R
authors.initials: R
authors.lastname: Movshovich
authors.forename: J L
authors.initials: JL
authors.lastname: Sarrao
authors.forename: J D
authors.initials: JD
authors.lastname: Thompson
authors.forename: F
authors.initials: F
authors.lastname: Steglich