Correlation between the Kondo temperature and the photoemission spectral function in the CeSix (1.6 <= x <= 2) system.

In this paper, we study the evolution of the photoemission 4f-electron spectral density as a function of concentration in the CeSi x (1.6≤x≤2) system. The physical properties are strongly composition dependent around x=2 reflecting large variations of the Rondo temperature with Si vacancies. Then this system represents an ideal case for photoemission investigations since it is possible to tune the Rondo temperature without significant changes of the non-f-electron density of states. Our spectroscopic measurements show a correlation between the Rondo temperature and the 4f intensity near the Fermi level as expected in the framework of the single-impurity Anderson model