TY - JOUR
T1 - Photoemission evidence for valence fluctuations and Kondo resonance in YbAl 2
AU - Matsunami, Masaharu
AU - Chainani, Ashish
AU - Taguchi, Munetaka
AU - Eguchi, Ritsuko
AU - Takata, Yasutaka
AU - Oura, Masaki
AU - Yabashi, Makina
AU - Tamasaku, Kenji
AU - Nishino, Yoshinori
AU - Ishikawa, Tetsuya
AU - Kosaka, Masashi
AU - Shin, Shik
PY - 2012/7
Y1 - 2012/7
N2 - We use hard x-ray photoemission spectroscopy (HAXPES) to investigate the electronic structure of YbAl 2, for which the Yb valence has not been consistently reported to date. The bulk sensitivity and the analytical simplicity provided by the Yb 3d core-level HAXPES allow a reliable determination of the mean valence of Yb ions. For YbAl 2, it is evaluated to be +2.20, which remains nearly unchanged below 300 K. The Kondo resonance peak with an extremely high Kondo temperature (above 2000 K) is clearly identified in the valence-band spectra. The results indicate that a coherent Kondo state can be robust even in a nearly divalent system.
AB - We use hard x-ray photoemission spectroscopy (HAXPES) to investigate the electronic structure of YbAl 2, for which the Yb valence has not been consistently reported to date. The bulk sensitivity and the analytical simplicity provided by the Yb 3d core-level HAXPES allow a reliable determination of the mean valence of Yb ions. For YbAl 2, it is evaluated to be +2.20, which remains nearly unchanged below 300 K. The Kondo resonance peak with an extremely high Kondo temperature (above 2000 K) is clearly identified in the valence-band spectra. The results indicate that a coherent Kondo state can be robust even in a nearly divalent system.
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U2 - 10.1143/JPSJ.81.073702
DO - 10.1143/JPSJ.81.073702
M3 - Review article
AN - SCOPUS:84863565389
VL - 81
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
SN - 0031-9015
IS - 7
M1 - 073702
ER -