Kondo behaviour of the solid solution (Ce1−xLax)PtGa

The solid solution (Ce1−xLax)PtGa has been studied through X-ray diffraction, magnetization (σ(B)), magnetic susceptibility (χ(T)), electrical resistivity (ρ(T)), magnetoresistivity (MR) and heat capacity (CP(T)) measurements. The Néel temperature (TN=3.3 K) for CePtGa is lowered upon La substitution as observed from χ(T) and ρ(T) measurements. The Kondo temperature TK as calculated from MR measurements is comparable to TN and also decreases with La substitution. The volume dependence of TK is in accordance with the compressible Kondo lattice model and a Doniach diagram of the results is presented. CP(T) measurements are presented for CePtGa, Ce0.2La0.8PtGa and LaPtGa and the results are discussed in terms of the electronic and magnetic properties. Other features of interest are anomalies in ρ(T) and CP(T) due to crystalline electric field effects and metamagnetism as observed in σ(B) studies for samples with 0≤x≤ 0.3.