Kondo resonance in magnetic and non-magnetic Ce-intermetallics

Abstract

Ce₂CoSi₃ is a Kondo lattice compound possessing non-magnetic ground state and Ce₂RhSi₃ exhibits antiferromagnetic ordering below 7 K. A substitution of Co at Rh sites leads the system to evolve from magnetically ordered phase to a non-magnetic phase due to Kondo effect via quantum critical point (QCP). Here, we review the electronic structure of these two compounds studied using high resolution photoemission spectroscopy. The valence band spectra of Ce₂CoSi₃ exhibit distinct Kondo resonance features as expected. Interestingly, the high resolution spectra of Ce₂RhSi₃ also reveal similar features, which are sensitive to temperature. The linewidth of the core level spectra are found to be influenced by the Kondo effect. All these results indicate the persistence of Kondo compensation below QCP (Kondo temperature, T_K ≠ 0 at QCP).