Isoelectronic tuning of heavy fermion systems: Proposal to synthesize Ce3Sb4Pd3

Article

关键词: KONDO INSULATOR;    SEMICONDUCTING PROPERTIES;    MAGNETIC-SUSCEPTIBILITY;    VALENCE;    GAP;    CE;    RESISTIVITY;    TRANSITIONS;    EXPANSION;    PRESSURE;   

DOI  :  10.1103/PhysRevB.101.035116

来源: SCIE

【 摘 要 】

The study of (quantum) phase transitions in heavy fermion compounds relies on a detailed understanding of the microscopic control parameters that induce them. While the influence of external pressure is rather straightforward, atomic substitutions are more involved. Nonetheless, replacing an elemental constituent of a compound with an isovalent atom is, effects of disorder aside, often viewed as merely affecting the lattice constant. Based on this picture of chemical pressure, the unit-cell volume is identified as an empirical proxy for the Kondo coupling. Here, instead, we propose an orbital scenario in which the coupling in complex systems can be tuned by isoelectronic substitutions with little or no effect onto cohesive properties. Starting with the Kondo insulator Ce3Bi4Pt3, we consider, within band theory, isoelectronic substitutions of the pnictogen (Bi -> Sb) and/or the precious metal (Pt -> Pd). We show for the isovoltune series Ce3Bi4(Pt1-xPdx)(3) that the Kondo coupling is in fact substantially modified by the different radial extent of the 5d (Pt) and 4d (Pd) orbitals, while spin-orbit coupling mediated changes are minute. Combining experimental Kondo temperatures with simulated hybridization functions, we also predict effective masses in*, finding excellent agreement with many-body results for Ce3Bi4Pt3. Our analysis motivates studying the so-far unknown Kondo insulator Ce3Sb4Pd3, for which we predict m*/m(band) = O(10).

【 授权许可】

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