Mixed-valence state in the dilute-impurity regime of La-substituted SmB₆.

ABSTRACT: Homogeneous mixed-valence (MV) behaviour is one of the most intriguing phenomena of f-electron systems. Despite extensive efforts, a fundamental aspect which remains unsettled is the experimental determination of the limiting cases for which MV emerges. Here we address this question for SmB₆, a prototypical MV system characterized by two nearly-degenerate Sm²⁺ and Sm³⁺ configurations. By combining angle-resolved photoemission spectroscopy (ARPES) and x-ray absorption spectroscopy (XAS), we track the evolution of the mean Sm valence, v_Sm, in the Sm_xLa_1-xB₆ series. Upon substitution of Sm ions with trivalent La, we observe a linear decrease of valence fluctuations to an almost complete suppression at x = 0.2, with v

SUBMITTER: Zonno M 

PROVIDER: S-EPMC11368937 | biostudies-literature | 2024 Sep

REPOSITORIES: biostudies-literature