Effects of La dilution on the CeNiAl4 Kondo lattice

We carried out the magnetic, electrical resistivity and heat capacity measurements for the Ce1−xLaxNiAl4 compounds. The values of the effective paramagnetic moment μeff were calculated from the Curie–Weiss constant. For all the solid solutions under study the μeff values are very close to 2.54μB found for cerium in the pure Ce metal. Resistivity studies on the Ce1−xLaxNiAl4 alloy system illustrate the transition from the Kondo regime (x = 0.0) to the single-ion Kondo regime (0.05 ≤ x ≤ 0.8). The substitution of Ce by La reduces the electronic heat capacity coefficient γ values from 154 mJ/mol K2 for CeNiAl4 to 4.8 mJ/mol K2 for LaNiAl4. At low temperatures γ value depends strongly on the temperature range used for the extrapolation.