title: Interplay between crystal field splitting and Kondo effect in CeNi9Ge(4-x)Si(x).
abstract: The pseudo-ternary solid solution CeNi(9)Ge(4-x)Si(x) (0 ≤ x ≤ 4) has been investigated by means of x-ray diffraction, magnetic susceptibility, specific heat, electrical resistivity, thermopower and inelastic neutron scattering studies. The isoelectronic substitution of germanium by silicon atoms causes a dramatic change of the relative strength of competing Kondo, RKKY and crystal field (CF) energy scales. The strongest effect is the continuous elevation of the Kondo temperature T(K) from approximately 3.5 K for CeNi(9)Ge(4) to about 70 K for CeNi(9)Si(4). This increase of the Kondo temperature is attended by a change of the CF level scheme of the Ce ions. The interplay of the different energy scales results in an incipient reduction of the ground state degeneracy from an effectively fourfold degenerate non-magnetic Kondo ground state with unusual non-Fermi-liquid features of CeNi(9)Ge(4) to a lower one, followed by an increase towards a sixfold, fully degenerate ground state multiplet in CeNi(9)Si(4) (T(K) ∼ Δ(CF)).
authors.affiliation: CPM, Institut für Physik, Universität Augsburg, Augsburg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Gold
authors.forename: P
authors.initials: P
authors.lastname: Gross
authors.forename: L
authors.initials: L
authors.lastname: Peyker
authors.forename: G
authors.initials: G
authors.lastname: Eickerling
authors.forename: G G
authors.initials: GG
authors.lastname: Simeoni
authors.forename: O
authors.initials: O
authors.lastname: Stockert
authors.forename: E
authors.initials: E
authors.lastname: Kampert
authors.forename: F
authors.initials: F
authors.lastname: Wolff-Fabris
authors.forename: H
authors.initials: H
authors.lastname: Michor
authors.forename: E-W
authors.initials: EW
authors.lastname: Scheidt