title: Dilution and non-Fermi-liquid effects in the CePtIn Kondo lattice.
abstract: Measurements of electrical resistivity (ρ(T)), magnetoresistivity (MR), magnetic susceptibility (χ(T)) and heat capacity (C(P)(T)) are presented for the (Ce(1-x)La(x))PtIn alloy system of which the CePtIn parent is a known dense Kondo compound that does not order magnetically down to 50 mK. χ(T) for alloys 0≤x≤0.8 exhibits Curie-Weiss behaviour. ρ(T) results indicate a transition from a dense Kondo behaviour for 0≤x≤0.2 to a single-ion Kondo region (0.3≤x≤0.8). The Kondo energy scale as given by T(K) values calculated from MR studies and by the temperature T(max)(ρ(mag)) where the magnetic contribution to ρ(T) exhibits a maximum value, is compared with theoretical models. It is shown that the experimental results not only depend on a volume effect as given by the compressible Kondo lattice model of Lavagna but in addition confirm the more complex behaviour recently presented by Burdin and Fulde for a Kondo alloy system in which the magnetic (Ce) and non-magnetic (La) atoms are distributed randomly. Non-Fermi-liquid behaviour is predicted by Burdin and Fulde at certain critical concentrations of the alloy system and experimental evidence for this is presented through χ(T), ρ(T) and C(P)(T) measurements.
authors.affiliation: School of Physics, University of the Witwatersrand, Private Bag 3, PO WITS 2050, Johannesburg, South Africa. Physics Department, University of Johannesburg, PO Box 524, Aucklandpark 2006, South Africa.
authors.forename: F C
authors.initials: FC
authors.lastname: Ragel
authors.forename: P de V du
authors.initials: Pde V
authors.lastname: Plessis
authors.forename: A M
authors.initials: AM
authors.lastname: Strydom