Effects of la dilution on the CePt₂Si₂ Kondo lattice

Electrical resistivity (ρ(T)) and magnetoresistivity (MR) measurements are presented for the (Ce_1-xLa_x)Pt₂Si ₂ alloy system. ρ(T) data at low temperatures for alloys in the concentrated Kondo lattice regime 0≤x≤0.2 conform to a ρ(T) = ρ₀+AT² dependence and Fermi-liquid parameters A and T_coh are presented. The maximum that occurs in ρ(T) in the concentrated Kondo lattice regime at a temperature of T_max is no longer observed for samples with x≥0.3 which show single-ion Kondo behaviour. MR measurements on alloys with x = 0.5, 0.7 and 0.9 yield values of the Kondo temperature T_K through Schlottmann analysis. The dependences of A, T_max and T_K on x are discussed in terms of the volume and Kondo hole effects occurring upon alloying. Anomalies in ρ(T) for LaPt ₂Si₂ and some of the alloy samples are also reported.