Effect of annealing on the electrical resistivity of Kondo lattice CeRh₂Ga₂

CeRh 2 Ga 2 , which crystallizes in CaBe 2 Ge 2 -type primitive tetragonal structure (space group P 4/ nmm ), is known to exhibit Kondo lattice heavy fermion behavior and is proposed to be a potential candidate for Weyl-Kondo semimetal phase. Here we examine the effect of annealing, particularly on the electrical resistivity of polycrystalline CeRh 2 Ga 2 . A comparative study of the powder x-ray diffraction (XRD), magnetic susceptibility χ ( T ), heat capacity C p ( T ) and electrical resistivity ρ ( T ) data of both as-arc-melted and annealed CeRh 2 Ga 2 samples are presented. The XRD patterns of both as-arc-melted and annealed samples look similar. No marked effect of annealing could be clearly seen in the temperature dependences of χ and C p data. However, the effect of annealing is clearly manifested in the T dependence of ρ , particlularly at low temperatures. At low- T the ρ ( T ) data of as-arc-melted CeRh 2 Ga 2 follow a T 2 temperature dependence (Fermi-liquid feature), whereas the ρ ( T ) data of annealed CeRh 2 Ga 2 exhibit an upturn (semimetal-like feature).