Non-Fermi liquid behavior in U3−xNi3Sn4−y single crystals

X-ray absorption fine structure and field-dependent specific heat measurements of non-Fermi liquidU3Ni3Booth1, Shlyk2, Nenkov3 et al. 2004Phys. Rev. B

“…22 Regardless, in the NFL region, the electrical resistivity goes as ⌬ϭ(T)Ϫ 0 ϳT 1.79 . 1 This dependence is roughly consistent with the AF-QCP result of ⌬ϳT 1.5 , if one allows for the possibility, as discussed in Ref. 9, that the non-Fermi-liquid regions of the Fermi surface only occupy so called ''hot lines'' where magnetic scattering dominates, and that the rest of the Fermi surface constitutes a Fermi-liquid regime that could dominate the conductivity.…”

“…The stoichiometries of the single crystals has been confirmed by single-crystal x-ray diffraction measurements and are, in fact, the same samples as those reported in Ref. 1. Polycrystalline sample stoichiometries are only nominally based on the composition of the starting materials.…”

“…22 In addition, these data are qualitatively consistent with the two-channel Kondo model, 24 -27 although fits using this model require an unrealistically high spin-fluctuation energy. 1 Comparisons to the KDM are not favorable either, since the KDM predicts logarithmic divergences of the magnetic susceptibility and specific heat and a linear temperature dependence of the electrical resistivity, all of which are clearly at odds with the experimental data. In addition, measurements at applied pressures up to 1.8 GPa ͑Ref.…”

“…1 For instance, the low-temperature magnetic susceptibility diverges as T Ϫ0.3 , the leading coefficient for the electronic term in the specific heat ␥ϭC el /T varies as ϪT 0.5 , and the resistivity varies as T 1.79 . Such behavior is at odds with the standard Fermi liquid ͑FL͒ description ( ϳC el /Tϳconst., ⌬ϳT 2 ) of Landau.…”

“…Moreover, the residual resistivity is as low as 7 ⍀ cm. 1 Nevertheless, some forms of lattice disorder can be difficult to detect using standard diffraction techniques. For instance, if disorder occurs in a nonperiodic fashion, such as in amorphous regions or very small domains, only a local structural probe such as x-ray absorption fine-structure ͑XAFS͒ or pairdistribution function analysis of powder diffraction data will be sensitive to it.…”