Local structure and site occupancy of Cd and Hg substitutions in CeTIn5 (T=Co, Rh, Ir)

Abstract

The CeTIn5 superconductors (T=Co, Rh, or Ir) have generated great interest due to their relatively Tc's, NFL behavior, and their proximity to AF order and quantum critical points. In contrast to small changes with the T-species, electron doping in CeT(In{1-x}Mx)5 with M=Sn and hole doping with Cd or Hg have a dramatic effect on the electronic properties at very low concentrations. The present work reports EXAFS measurements that address the substituent atom distribution as a function of T, M, and x, near the superconducting phase. Together with previous measurements for M=Sn, the proportion of the M atom residing on the In(1) site, f{In(1)}, increases in the order M=Cd, Sn, and Hg, ranging from about 40% to 70%, showing a strong preference for these substituents to occupy the In(1) site (random=20%). In addition, f{In(1)} ranges from 70% to 100% for M=Hg in the order T=Co, Rh, and Ir. These fractions track the changes in the atomic radii of the various species, and help explain the sharp dependence of Tc on substituting into the In site. However, it is difficult to reconcile the small concentrations of M with the dramatic changes in the ground state in the hole-doped materials with only an impurity scattering model. These results therefore indicate that while such substitutions have interesting local atomic structures with important electronic and magnetic consequences, other local changes in the electronic and magnetic structure are equally important in determining the bulk properties of these materials.

10 pages, 7 figures, to appear in PRB

References in corpus (10)

• Hidden Magnetism and Quantum Criticality in the Heavy Fermion Superconductor CeRhIn5
• Spin resonance in the d-wave superconductor CeCoIn5
• Modelling the Localized to Itinerant Electronic Transition in the Heavy Fermion System CeIrIn5
• Reversible Tuning of the Heavy Fermion Ground State in CeCoIn${}_5$
• Microscopic evidence for field-induced magnetism in CeCoIn${}_5$
• Interacting Antiferromagnetic Droplets in Quantum Critical CeCoIn_5
• Magnetic structure of Cd-doped CeCoIn5
• Incoherent non-Fermi liquid scattering in a Kondo lattice
• Observation of Spin Susceptibility Enhancement in the Possible FFLO State in CeCoIn${}_5$
• Nuclear magnetic resonance in the heavy fermion superconductors

Cited by in corpus (12)

• Visualizing heavy fermions emerging in a quantum critical Kondo lattice
• Electronic tuning and uniform superconductivity in CeCoIn5
• Evolution of ground state wave function in CeCoIn${}_5$ upon Cd or Sn doping
• In Situ STM Observation of Nonmagnetic Impurity Effect in MBE-grown CeCoIn${}_5$ Films
• Resolution of the discrepancy between the variation of the physical properties of Ce1-xYbxCoIn5 single crystals and thin films with Yb composition
• Fermi surface evolution through a heavy fermion superconductor-to-antiferromagnet transition: de Haas-van Alphen effect in Cd-substituted CeCoIn${}_5$
• Controlling unconventional superconductivity in artificially engineered $f$-electron Kondo superlattices
• Magnetic, thermal and transport properties of Cd doped CeIn${}_3$
• DFT+DMFT study of dopant effect in a heavy fermion compound CeCoIn5
• Magnetic and superconducting properties of the heavy-fermion CeCoIn5 epitaxial film probed by nuclear quadrupole resonance
• Strong pinning of vortices by antiferromagnetic domain boundaries in CeCo(In${}_{1-x}$Cd${}_x$)${}_5$
• Tuning the pressure-induced superconductivity in Pd-substituted CeRhIn5