Thermodynamic and electrical transport properties of CeRhSb[formula omitted]Te[formula omitted] systems: Transition from Kondo insulating to the Griffiths and non-Fermi liquid states

Abstract

It follows from our analysis of CeRhSb that the formation of Kondo insulator state due to the presence of the collective spin singlet state is strongly reduced by its doping with various dopants when their amount exceeds 8%–10%, regardless of whether they are substitute Ce, Rh or Sb. A wide variety of experimental results (electrical resistivity ρ, magnetic susceptibility χ, specific heat C, x-ray photoelectron spectroscopy) and theoretical investigations have convincingly demonstrated the proposed earlier scaling law χ×ρ=const. in the Kondo insulator regime, which is universal for all known Kondo insulators. We also analyze the properties of the Griffiths phase for CeRhSb when Pd substitutes Rh, or Sb is fractionally replaced by Te or Sn, whereas doping of Ce with La leads to the formation of magnetic cluster structure as a result of the Kondo hole effect. Magnetoresistance of CeRhSb as a function of the field B shows a negative B2 behavior, which is characteristic of the Kondo–lattice systems, it is also documented for various topological materials. Electrical resistivity of CeRhSb, as well as of CeRhSb1−xTex (x≤0.6) and CeRh1−xPdxSb (x≤0.04), follows ρ=ρ0−AT law between 0.4 and ∼2.5 K, which suggests a non-Fermi liquid-like behavior due to presence of the Griffiths phase.