Electronic correlations in FeGa${}_3$ and the effect of hole doping on its magnetic properties

Abstract

We investigate signatures of electronic correlations in the narrow-gap semiconductor FeGa${}_3$ by means of electrical resistivity and thermodynamic measurements performed on single crystals of FeGa${}_3$, Fe${}_{1-x}$Mn${}_x$Ga${}_3$ and FeGa${}_{3-y}$Zn${}_y$, complemented by a study of the 4$d$ analog material RuGa${}_3$. We find that the inclusion of sizable amounts of Mn and Zn dopants into FeGa${}_3$ does not induce an insulator-to-metal transition. Our study indicates that both substitution of Zn onto the Ga site and replacement of Fe by Mn introduces states into the semiconducting gap that remain localized even at highest doping levels. Most importantly, using neutron powder diffraction measurements, we establish that FeGa${}_3$ orders magnetically above room temperature in a complex structure, which is almost unaffected by the doping with Mn and Zn. Using realistic many-body calculations within the framework of dynamical mean field theory (DMFT), we argue that while the iron atoms in FeGa${}_3$ are dominantly in an $S=1$ state, there are strong charge and spin fluctuations on short time scales, which are independent of temperature. Further, the low magnitude of local contributions to the spin susceptibility advocates an itinerant mechanism for the spin response in FeGa${}_3$. Our joint experimental and theoretical investigations classify FeGa${}_3$ as a correlated band insulator with only small dynamical correlation effects, in which non--local exchange interactions are responsible for the spin gap of 0.4 eV and the antiferromagnetic order. We show that hole doping of FeGa${}_3$ leads, within DMFT, to a notable strengthening of many--body renormalizations.

arXiv comment19 pages, 16 figures

References in corpus (33)

• Electronic Structure Calculations with Dynamical Mean-Field Theory: A Spectral Density Functional Approach
• Quantum Cluster Theories
• A continuous-time solver for quantum impurity models
• Quantum Monte Carlo Impurity Solver for Cluster DMFT and Electronic Structure Calculations in Adjustable Base
• Dynamical Mean-Field Theory within the Full-Potential Methods: Electronic structure of Ce-115 materials
• Rare region effects at classical, quantum, and non-equilibrium phase transitions
• Polaronic hole localization and multiple hole binding of acceptors in oxide wide-gap semiconductors
• The coherence-incoherence crossover and the mass-renormalization puzzles in Sr2RuO4
• Anisotropy and large magnetoresistance in narrow gap semiconductor FeSb2
• Kondo Insulator description of spin state transition in FeSb2
• Signatures of electronic correlations in iron silicide
• Self consistent GW determination of the interaction strength: application to the iron arsenide superconductors
• Effective band-structure in the insulating phase versus strong dynamical correlations in metallic VO2
• Thermopower of correlated semiconductors : application to FeAs2 and FeSb2
• Optical investigation of the metal-insulator transition in $FeS{b}_2$
• Metal-insulator transition and magnetism in correlated band insulator: FeSi and Fe${}_{1-x}$Co${}_x$Si
• First-order transition between a small-gap semiconductor and a ferromagnetic metal in the isoelectronic alloys FeSi${}_{1-x}$Ge${}_x$
• First order transition from correlated electron semiconductor to ferromagnetic metal in single crystalline FeSi1-xGex
• Model for FeSi, a strongly correlated insulator
• Temperature dependent correlations in covalent insulators
• From antiferromagnetic insulator to correlated metal in pressurized and doped LaMnPO
• Transport, Thermal, and Magnetic Properties of the Narrow-Gap Semiconductor CrSb2
• The semiconductor-to-ferromagnetic-metal transition in FeSb2
• Correlations in a band insulator
• Ferromagnetic Instability in a Doped Band-Gap Semiconductor FeGa${}_3$
• Incommensurate spin density wave in Co-doped BaFe2As2
• Anisotropy in magnetic and transport properties of Fe1-xCoxSb2
• Interplay between localized and itinerant magnetism in Co substituted FeGa${}_3$
• Effect of Chemical Doping on the Thermoelectric Properties of FeGa3
• Anisotropy in the magnetic and electrical transport properties of Fe1-xCrxSb2
• Itinerant origin of the ferromagnetic quantum critical point in Fe(Ga,Ge)3
• Interesting magnetic properties of Fe${}_{1-x}$Co${}_x$Si alloys
• Weak Ferromagnetism in Fe1-xCoxSb2

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• Spin dynamics of FeGa${}_{3-x}$Ge${}_x$ studied by Electron Spin Resonance
• Optical conductivity and vibrational spectra of the narrow-gap semiconductor FeGa${}_3$
• Prototypical many-body signatures in transport properties of semiconductors