Optical study of archetypical valence-fluctuating Eu-systems

Abstract

We have investigated the optical conductivity of the prominent valence fluctuating compounds EuIr2Si2 and EuNi2P2 in the infrared energy range to get new insights into the electronic properties of valence fluctuating systems. For both compounds we observe upon cooling the formation of a renormalized Drude response, a partial suppression of the optical conductivity below 100 meV and the appearance of a mid-infrared peak at 0.15 eV for EuIr2Si2 and at 0.13 eV for EuNi2P2. Most remarkably, our results show a strong similarity with the optical spectra reported for many Ce- or Yb-based heavy fermion metals and intermediate valence systems, although the phase diagrams and the temperature dependence of the valence differ strongly between Eu- and Ce-/Yb-systems. This suggests that the hybridization between 4f- and conduction electrons, which is responsible for the properties of Ce- and Yb-systems, plays an important role in valence fluctuating Eu-systems.

References in corpus (12)

• Kramers-Kronig constrained variational analysis of optical spectra
• Heavy Fermions and Quantum Phase Transitions
• Exact solution of the Falicov-Kimball model with dynamical mean-field theory
• Signatures of valence fluctuations in CeCu2Si2 under high pressure
• Enhanced Valence Fluctuations Caused by f-c Coulomb Interaction in Ce-Based Heavy Electrons: Possible Origin of Pressure-Induced Enhancement of Superconducting Transition Temperature in \Ge and Related Compounds
• Structural, Thermal, Magnetic and Electronic Transport Properties of the LaNi2(Ge{1-x}P{x})2 System
• Pseudogap Formation and Heavy Carrier Dynamics in Intermediate Valence YbAl3
• Observation of an optical non-Fermi-liquid behavior in the heavy fermion state of YbRh${}_2$Si${}_2$
• Optical study of the electronic phase transition of strongly correlated YbInCu_4
• New Universality Class of Quantum Criticality in Ce- and Yb-based Heavy Fermions
• Gutzwiller Method for an Extended Periodic Anderson Model with the c-f Coulomb Interaction
• Temperature- and Magnetic-Field-Dependent Optical Properties of Heavy Quasiparticles in YbIr2Si2

Cited by in corpus (13)

• Charge-density wave, superconductivity and $f$-electron valence instability in EuBiS${}_2$F
• Anomalous Eu Valence State and Superconductivity in Undoped Eu3Bi2S4F4
• Europium mixed-valence, long-range magnetic order, and dynamic magnetic response in EuCu${}_2$(Si${}_x$Ge${}_{1-x}$)${}_2$
• Interplay of Dirac fermions and heavy quasiparticles in solids
• Infrared properties of heavy-fermions: evolution from weak to strong hybridizations
• Magnetic structure of divalent europium compound EuGa${}_4$ studied by single crystal time-of-flight neutron diffraction
• Novel Valence Transition in Elemental Metal Europium around 80 GPa
• Valence effect on the thermopower of Eu systems
• Charge, lattice and magnetism across the valence crossover in EuIr${}_2$Si${}_2$ single crystals
• Valence fuctuation and magnetic ordering in EuNi2(P1-xGex)2 single crystals
• Hybridization and Correlation between f- and d-orbital electrons in a valence fluctuating compound EuNi2P2
• Study of photoinduced valence dynamics in EuNi${}_2$(Si${}_{0.21}$Ge${}_{0.79}$)${}_2$ through time-resolved X-ray absorption spectroscopy
• Microscopic Observation of Heavy Quasiparticle Formation in the Intermediate Valence Compound EuNi${}_2$P${}_2$: ${}^{31}$P NMR Study