Yb LIII-edge and Cu K-edge x-ray absorption spectroscopy in YbCdCu4 and YbInCu4

Temperature Dependence of the Kondo Resonance Peak in Photoemission Spectra of Rare-Earth Compound YbMgCu4

“…Recent photoemission studies on YbCdCu 4 have revealed an enhancement of the peak intensity at low temperatures [13]. For the case of YbMgCu 4 , where T K is three to four times larger than that of YbCdCu 4 , the intense peak remains in a wide temperature range 8 ≤ T ≤ 187 K, demonstrating the robustness of the Kondo singlet state [16]. Therefore, the 4 f 7/2 peak at |ω| ∼ 69 meV is responsible for the heavy-fermion behavior of YbMgCu 4 .…”