Effect of Pressure on Heavy-Fermion Metals

Lin, Hai; Li, Zheng-zhong; Xiao, Mao; Xu, Xiaoli

doi:10.1088/0253-6102/31/1/49

Cited by 7 publications

(2 citation statements)

References 5 publications

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“…This means that it is possible to observe a reduction of hybridization in both the specific heat and magnetic susceptibility measurements. Theoretical investigations of the pressure effects on Yb-based compounds [34] show that the linear coefficient of the specific heat and Pauli-like magnetic susceptibility increase with positive pressure, which is therefore consistent with the idea of negative pressure effects on Yb inside the Zn cage supported by our experimental results.…”

Section: Analysis and Discussionsupporting

confidence: 90%

Tuning the electronic hybridization in the heavy fermion cage compound YbFe₂Zn₂₀with Cd doping

Cabrera-Baez

Ribeiro

Ávila

2016

J. Phys.: Condens. Matter

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Abstract.Tuning of the electronic properties of heavy fermion compounds by chemical substitutions provides excellent opportunities to further understand the physics of hybridized ions in crystal lattices. Here we present an investigation on the effects of Cd doping in flux-grown single crystals of the complex intermetallic cage compound YbFe 2 Zn 20 , that has been described as a heavy fermion with Sommerfeld coefficient of 535 mJ/mol.K 2 . Substitution of Cd for Zn disturbs the system by expanding the unit cell and, in this case, the size of the Zn cages that surround Yb and Fe. With increasing amount of Cd, the hybridization between Yb 4f electrons and the conduction electrons is weakened, as evidenced by a decrease in the Sommerfeld coefficient, which should be accompanied by a valence shift of the Yb 3+ due to the negative chemical pressure effect. This scenario is also supported by the low temperature dc-magnetic susceptibility, that is gradually suppressed and evidences an increment of the Kondo temperature, based on a shift to higher temperatures of the characteristic broad susceptibility peak. Furthermore, the DC resistivity decreases with the isoelectronic Cd substitution for Zn, contrary to the expectation for an increasingly disordered system, and implying that the valence shift is not related to charge carrier doping. The combined results demonstrate excellent complementarity between positive physical pressure and negative chemical pressure, and point to a rich playground for exploring the physics and chemistry of strongly correlated electron systems in the general family of Zn 20 compounds, despite their structural complexity.

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Section: Analysis and Discussionsupporting

confidence: 90%

Tuning the electronic hybridization in the heavy fermion cage compound YbFe₂Zn₂₀with Cd doping

Cabrera-Baez

Ribeiro

Ávila

2016

J. Phys.: Condens. Matter

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“…Figure A2 also shows the energy shift of the DOS maxima with P in the vicinity of ò F to higher binding energy E | | in respect to ò F . This response for heavy Fermi metals to the applied pressure is characteristic of electron-type conductivity at high pressure [71]. Figure A4.…”

Section: Discussionmentioning

confidence: 95%

The effective increase in atomic scale disorder by doping and superconductivity in Ca₃Rh₄Sn₁₃

et al. 2018

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A comprehensive study of the electronic structure, thermodynamic and electrical transport properties reveals the existence of inhomogeneous superconductivity due to structural disorder in Ca 3 Rh 4 Sn 13 doped with La (Ca 3−x La x Rh 4 Sn 13 ) or Ce (Ca 3−x Ce x Rh 4 Sn 13 ) with superconducting critical temperatures T c  higher than those (T c ) observed in the parent compounds. The T−x diagrams and the entropy S(x) T isotherms document well the relation between the degree of atomic disorder and separation of the high-temperature T c  and T c -bulk phases. In these dirty superconductors, with the mean free path much smaller than the coherence length, the Werthamer-Helfand-Hohenber theoretical model does not fit well the H c2 (T) data. We demonstrate that this discrepancy can result from the presence of strong inhomogeneity or from two-band superconductivity in these systems. Both the approaches very well describe the H−T dependencies, but the present results as well as our previous studies give stronger arguments for the scenario based on the presence of nanoscopic inhomogeneity of the superconducting state. A comparative study of La-doped and Ce-doped Ca 3 Rh 4 Sn 13 showed that in the disordered Ca 3−x Ce x Rh 4 Sn 13 alloys the presence of spin-glass effects is the cause of the additional increase of T c  in respect to the critical temperatures of disordered Ca 3−x La x Rh 4 Sn 13 . We also revisited the nature of structural phase transition at T 130 170 ~¸K and documented that there might be another precursor transition at higher temperatures. Raman spectroscopy and thermodynamic properties suggest that this structural transition may be associated with a CDW-type instability.

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Two Types of Pressure Dependence of Residual Resistivity in Doped Kondo Insulators

Yi-Zhe¹,

Li²,

Xiao³

et al. 2004

Chinese Phys. Lett.

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Effect of Pressure on Heavy-Fermion Metals

Cited by 7 publications

References 5 publications

Tuning the electronic hybridization in the heavy fermion cage compound YbFe₂Zn₂₀with Cd doping

Tuning the electronic hybridization in the heavy fermion cage compound YbFe₂Zn₂₀with Cd doping

The effective increase in atomic scale disorder by doping and superconductivity in Ca₃Rh₄Sn₁₃

Two Types of Pressure Dependence of Residual Resistivity in Doped Kondo Insulators

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Effect of Pressure on Heavy-Fermion Metals

Cited by 7 publications

References 5 publications

Tuning the electronic hybridization in the heavy fermion cage compound YbFe2Zn20with Cd doping

Tuning the electronic hybridization in the heavy fermion cage compound YbFe2Zn20with Cd doping

The effective increase in atomic scale disorder by doping and superconductivity in Ca3Rh4Sn13

Two Types of Pressure Dependence of Residual Resistivity in Doped Kondo Insulators

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Product

Resources

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Tuning the electronic hybridization in the heavy fermion cage compound YbFe₂Zn₂₀with Cd doping

Tuning the electronic hybridization in the heavy fermion cage compound YbFe₂Zn₂₀with Cd doping

The effective increase in atomic scale disorder by doping and superconductivity in Ca₃Rh₄Sn₁₃