Reduction of Kondo lattice effects in Yb_1−xLu_xAl₃observed by soft x-ray photoelectron spectroscopy

Different evolution of the intrinsic gap in strongly correlated SmB6in contrast to YbB12

“…On the other hand, the Yb 4f peak shift toward E F is ∼20 meV for x = 0 whereas it is at most 10 meV for x = 0.125 in Yb 1−x Lu x B 12 (figure 1(b)). As argued previously for YbAl 3 [36,37] 21 but not for YbInCu 4 [38] 22 , peak shifts with temperature of this magnitude are greater than predicted in the single-impurity Anderson model and so are considered to be a 4f lattice coherence effect. The temperature dependence of the 4f peaks observed for x = 0 and 0.15 in Sm 1−x Eu x B 6 is qualitatively similar to that for pure YbB 12 and YbAl 3 in which the Yb 4f lattice coherence is essential for the peak shift.…”

Kondo lattice effects and the collapse of lattice coherence inYb1−xLuxB12studied by hard x-ray photoelec

“…In Lu-substituted dense Kondo metal Yb 0.6 Lu 0.4 Al 3 , we have also confirmed that the detailed T dependence of the Yb 4f spectra is well understood within the SIAM. 53 In addition, we have confirmed that the T dependence for x =1/ 8 cannot be sufficiently reproduced if the CEF splitting is not taken into account in the calculations. If the CEF splittings were neglected, the 4f 12 peak shifts from 200 to 20 K are overestimated as 50-60 meV ͑data not shown͒.…”

Breakdown of the coherence effects and Fermi liquid behavior in YbAl3nanoparticles

“…Moreover, studies on the Yb 1−x Lu x Al 3 series of alloys have shown that according to magnetic susceptibility and specific heat measurements, the appearance of a second energy scale at 40 K in the intermediate valence Kondo lattice YbAl 3 is a true coherence effect [14]. In addition, a reduction of Kondo lattice effects in Yb 1−x Lu x Al 3 has been observed by soft x-ray photoelectron spectroscopy, with behavior in good agreement with the single impurity Anderson model [15]. However, it is interesting to note that details of these changes in the Kondo lattice behavior have not so far been explored by means of electrical resistivity (ρ(T)) measurements in this Yb-substituted series, despite its representing a valuable source of evidence to disclose the evolution of the coherence effects and the Kondo regime in strongly correlated Yb and Ce compounds.…”