TY - JOUR
T1 - Electronic structure of heavy fermion uranium compounds studied by core-level photoelectron spectroscopy
AU - Fujimori, Shin Ichi
AU - Ohkochi, Takuo
AU - Kawasaki, Ikuto
AU - Yasui, Akira
AU - Takeda, Yukiharu
AU - Okane, Tetsuo
AU - Saitoh, Yuji
AU - Fujimori, Atsushi
AU - Yamagami, Hiroshi
AU - Haga, Yoshinori
AU - Yamamoto, Etsuji
AU - Tokiwa, Yoshifumi
AU - Ikeda, Shugo
AU - Sugai, Takashi
AU - Ohkuni, Hitoshi
AU - Kimura, Noriaki
AU - Onuki, Yoshichika
PY - 2012/1/1
Y1 - 2012/1/1
N2 - High-energy-resolution core-level and valence-band photoelectron spectroscopic studies were performed for the heavy fermion uranium compounds UGe 2, UCoGe, URhGe, URu 2Si 2, UNi 2Al 3, UPd 2, and UPt 3 as well as typical localized and itinerant uranium compounds to understand the relationship between the uranium valence state and their core-level spectral line shapes. In addition to the main line and high-binding energy satellite structure recognized in the core-level spectra of uranium compounds, a shoulder structure on the lower binding energy side of the main lines of localized and nearly localized uranium compounds was also found. The spectral line shapes show a systematic variation depending on the U 5f electronic structure. The core-level spectra of UGe 2, UCoGe, URhGe, URu 2Si 2, and UNi 2Al 3 are rather similar to those of itinerant compounds, suggesting that U 5f electrons in these compounds are well hybridized with ligand states. On the other hand, the core-level spectra of UPd 2Al 3 and UPt 3 show considerably different spectral line shapes from those of the itinerant compounds, suggesting that U 5f electrons in UPd 2Al 3 and UPt 3 are less hybridized with ligand states, leading to the correlated nature of U 5f electrons in these compounds. The dominant final state characters in their core-level spectra suggest that the numbers of 5f electrons in UGe 2, UCoGe, URhGe, URu 2Si 2, UNi 2Al 3, and UPd 2Al 3 are close to but less than three, while that of UPt 3 is close to two rather than to three.
AB - High-energy-resolution core-level and valence-band photoelectron spectroscopic studies were performed for the heavy fermion uranium compounds UGe 2, UCoGe, URhGe, URu 2Si 2, UNi 2Al 3, UPd 2, and UPt 3 as well as typical localized and itinerant uranium compounds to understand the relationship between the uranium valence state and their core-level spectral line shapes. In addition to the main line and high-binding energy satellite structure recognized in the core-level spectra of uranium compounds, a shoulder structure on the lower binding energy side of the main lines of localized and nearly localized uranium compounds was also found. The spectral line shapes show a systematic variation depending on the U 5f electronic structure. The core-level spectra of UGe 2, UCoGe, URhGe, URu 2Si 2, and UNi 2Al 3 are rather similar to those of itinerant compounds, suggesting that U 5f electrons in these compounds are well hybridized with ligand states. On the other hand, the core-level spectra of UPd 2Al 3 and UPt 3 show considerably different spectral line shapes from those of the itinerant compounds, suggesting that U 5f electrons in UPd 2Al 3 and UPt 3 are less hybridized with ligand states, leading to the correlated nature of U 5f electrons in these compounds. The dominant final state characters in their core-level spectra suggest that the numbers of 5f electrons in UGe 2, UCoGe, URhGe, URu 2Si 2, UNi 2Al 3, and UPd 2Al 3 are close to but less than three, while that of UPt 3 is close to two rather than to three.
KW - Electronic structure
KW - Heavy fermion
KW - Photoelectron spectroscopy
KW - Uranium compounds
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U2 - 10.1143/JPSJ.81.014703
DO - 10.1143/JPSJ.81.014703
M3 - Article
AN - SCOPUS:84855266333
VL - 81
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
SN - 0031-9015
IS - 1
M1 - 014703
ER -