Yb 4f states of YbXCu4 (X = Cd, Mg, Zn and Sn) investigated by high-resolution soft X-ray photoemission spectroscopy

Abstract

Yb 4f electronic structure of YbXCu 4 (X = Cd, Mg, Zn and Sn) has been investigated by means of high-resolution soft X-ray photoemission spectroscopy (SX-PES) with the excitation energy of hν = 800 eV, in comparison with the results of the valence transition compound YbInCu 4. The SX-PES spectra of YbCdCu 4 exhibit the temperature dependence similar to YbInCu 4, while those of the other YbXCu 4 compounds almost no temperature dependence. The X-dependence of the Yb 4f states suggests that the low In 5p density of states is important for the valence transition of YbInCu 4.