Kondo lattice heavy fermion behavior in CeRh₂Ga₂

The physical properties of an intermetallic compound CeRh₂Ga₂ have been investigated by magnetic susceptibility X(T), isothermal magnetization M(H), heat capacity C_p(T)electrical resistivity P(T), thermal conductivity and thermopower S(T) measurements. CeRh₂Ga₂ is found to crystallize with CaBe₂Ge₂-type primitive tetragonal structure (space group P4/nmm). No evidence of long range magnetic order is seen down to 1.8 K. The data show paramagnetic behavior with an effective moment μ_eff ≈ 2.5 μ_B/Ce³⁺ indicating Ce³⁺ valence state of Ce ions. The data exhibit Kondo lattice behavior with a metallic ground state. The low-T C_p(T) data yield an enhanced Sommerfeld coefficient γ =130(2)mJ/mol K² characterizing CeRh₂Ga₂ as a moderate heavy fermion system. The high-T C_p(T) p(T)and show an anomaly near 255 K, reflecting a phase transition. The suggests phonon dominated thermal transport with considerably higher values of Lorenz number L(T) compared to the theoretical Sommerfeld value L ₀.