Electronic structure of EuAl
studied by photoelectron spectroscopy
Kobata, Masaaki
; Fujimori, Shinichi
; Takeda, Yukiharu
; Okane, Tetsuo
; Saito, Yuji
; Kobayashi, Keisuke*; Yamagami, Hiroshi; Nakamura, Ai*; Hedo, Masato*; Nakama, Takao*; Onuki, Yoshichika*
The electronic structure of a divalent
compound EuAl
, which shows the charge density wave transition at
, was studied by the hard X-ray angle-integrated photoelectron spectroscopy (HAXPES) and the soft X-ray angle resolved photoelectron spectroscopy (ARPES). The valence band and core-level spectra obtained by the HAXPES are consistent with the divalent nature of Eu atoms in EuAl
. Furthermore, the Fermi surface as well as the band structure in the vicinity of the Fermi Energy (
) of EuAl
are very similar to those of its isostructural divalent
compound SrAl
, which does not have
electrons. These suggest that Eu atoms are divalent in EuAl
, and
electrons are completely localized with
electronic configuration in the ground state. The ARPES spectra measured along the
-
-Z high-symmetry line did not show significant temperature dependences above and below
within the energy resolution of
. Moreover, the Fermi surface mapping along the
direction showed that both of EuAl
and SrAl
have highly three-dimensional electronic structures, suggesting that the nesting of Fermi surface is not straightforward. The Fermi surface and band structure of SrAl
were well explained by the band-structure calculation based on the local density approximation.