Electronic structure of the intermediate-valence compound EuNiP studied by soft X-ray photoemission spectroscopy

中間価数物質EuNiPの電子構造の軟X線光電子分光法による研究

川崎 郁斗  ; 小畠 雅明  ; 藤森 伸一   ; 竹田 幸治   ; 山上 浩志; 辺土 正人*; 仲間 隆男*; 大貫 惇睦*

Kawasaki, Ikuto; Kobata, Masaaki; Fujimori, Shinichi; Takeda, Yukiharu; Yamagami, Hiroshi; Hedo, Masato*; Nakama, Takao*; Onuki, Yoshichika*

We carried out angle-resolved photoemission (ARPES) experiments using soft X rays to investigate the electronic structure of the intermediate valence compound EuNiP. Both the Eu and Eu components arising from the 4 and 4 final states were observed in the valence spectra, directly confirming an intermediate character of Eu ions. The three-dimensional band structure was studied by ARPES measurements, and we found that the ARPES spectra up to just below the Fermi level can well be explained by a calculation based on the density-functional theory for the non-4 reference compound SrNiP. The heavy-fermion bands in EuNiP are thus considered to be formed through the hybridization between the dispersive valence bands, which resemble those for SrNiP, and the Eu components located at the very vicinity of the Fermi level.