Magnetic and transport studies on R₃Pt₂₃Si₁₁ (R=La and Ce) compounds with dilute rare earth content

Abstract

Magnetic susceptibility, electrical resistivity, and low temperature heat capacity measurements have been carried out on R₃Pt₂₃Si₁₁ (R=La and Ce) compounds in which the rare earth content is only ~8 mole %. The La compound is a Pauli paramagnet down to 1.8 K while the susceptibility of the Ce compound shows a Curie-Weiss behavior with μ_eff=2.48μ_B and θ_P=-4K. The specific heat of the Ce compound shows a large upturn below 0.6 K, indicative of the onset of magnetic ordering in this compound. The electronic specific heat coefficient, γ, is found to be 19.2 mJ/mole K per formula unit for the La compound. The electrical resistivity of these compounds is typical of metallic systems. No Kondo-like anomaly is seen in the resistivity of Ce₃Pt₂₃Si₁₁. Superconductivity, most likely associated with an impurity phase, is observed in La₃Pt₂₃Si₁₁ at 1.7 K.