TY - JOUR
T1 - Interlayer states arising from anionic electrons in the honeycomb-lattice-based compounds AeAlSi (Ae=Ca, Sr, Ba)
AU - Lu, Yangfan
AU - Tada, Tomofumi
AU - Toda, Yoshitake
AU - Ueda, Shigenori
AU - Wu, Jiazhen
AU - Li, Jiang
AU - Horiba, Koji
AU - Kumigashira, Hiroshi
AU - Zhang, Yaoqing
AU - Hosono, Hideo
N1 - Funding Information:
The project was supported by Ministry of Education, Culture, Sports, Science and Technology (MEXT) Element Strategy Initiative and ACCEL of JST in Japan. The HAXPES measurements were performed with the approval of NIMS Synchrotron X-ray Station (Proposals No. 2015A4703 and No. 2015B4703). S.U. is grateful to HiSOR (Hiroshima University) and JAEA/SPring-8 for the development of HAXPES at BL15XU of SPring-8. The work at KEK-PF was performed under the approval of the Program Advisory Committee (Proposals No. 2013S2-002 and No. 2015S2-005) at the Institute of Materials Structure Science, KEK.
Publisher Copyright:
© 2017 American Physical Society.
PY - 2017/3/13
Y1 - 2017/3/13
N2 - We report that the interlayer states common to the compounds AeAlSi (Ae=Ca, Sr, Ba) arise from F-center-like electrons arrayed in periodic cavities. The SrPtSb-type intermetallic phases exhibit electrons localized to columns of the trigonal bipyramidal Ae3Al2 cages running perpendicular to the honeycomb layers. Ab initio calculations in combination with hard/soft x-ray photoemission spectroscopic measurements reveal that these features correspond to the anionic electrons that hybridize with apical Al3pz orbitals from the honeycomb layers above and below. Extra bands with a significant dispersion along the kz direction therefore contribute to the Fermi level in contrast to the apparent two-dimensional connectivity of the bonding in the compounds, and completely account for the presence of interlayer states. Our study demonstrates how the cage centers may serve as electronically important crystallographic sites, and extend the anionic electron concept into honeycomb lattice compounds.
AB - We report that the interlayer states common to the compounds AeAlSi (Ae=Ca, Sr, Ba) arise from F-center-like electrons arrayed in periodic cavities. The SrPtSb-type intermetallic phases exhibit electrons localized to columns of the trigonal bipyramidal Ae3Al2 cages running perpendicular to the honeycomb layers. Ab initio calculations in combination with hard/soft x-ray photoemission spectroscopic measurements reveal that these features correspond to the anionic electrons that hybridize with apical Al3pz orbitals from the honeycomb layers above and below. Extra bands with a significant dispersion along the kz direction therefore contribute to the Fermi level in contrast to the apparent two-dimensional connectivity of the bonding in the compounds, and completely account for the presence of interlayer states. Our study demonstrates how the cage centers may serve as electronically important crystallographic sites, and extend the anionic electron concept into honeycomb lattice compounds.
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U2 - 10.1103/PhysRevB.95.125117
DO - 10.1103/PhysRevB.95.125117
M3 - Article
AN - SCOPUS:85015958724
SN - 2469-9950
VL - 95
JO - Physical Review B
JF - Physical Review B
IS - 12
M1 - 125117
ER -