TY - JOUR
T1 - Energetics of endohedral atoms in type-I clathrates observed by soft x-ray spectroscopy
AU - Tang, Jun
AU - Rachi, Takeshi
AU - Kumashiro, Ryotaro
AU - Avila, Marcos A.
AU - Suekuni, Kouichirou
AU - Takabatake, Toshiro
AU - Guo, Fangzhun
AU - Kobayashi, Keisuke
AU - Akai, Koji
AU - Tanigaki, Katsumi
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2008/8/7
Y1 - 2008/8/7
N2 - We present an extensive soft x-ray photoelectron spectroscopy study on the core levels of the endohedral atoms of Ba8 Ga16 Ge30 (BGG), Sr8 Ga16 Ge30 (SGG), Eu8 Ga16 Ge30 (EGG), and Sr8 Ga16 Si30 (SGS) single crystals, performed at a high-energy facility. Unexpected features evidencing the different shift for the 2a and 6d sites between Ba4d and Sr3d are observed for BGG and SGG. The detailed analyses including theoretical support by first-principles band-structure calculations lead to the surprising conclusion that the component distributions of the larger tetrakaidecahedral cage are different depending on the endohedral atoms, which is in contrast to the past consensus that BGG and SGG have the same framework structure. The differences are further supported by analysis of the Ga3d core levels. This may suggest thorough reconsiderations on earlier interpretations of experimental data.
AB - We present an extensive soft x-ray photoelectron spectroscopy study on the core levels of the endohedral atoms of Ba8 Ga16 Ge30 (BGG), Sr8 Ga16 Ge30 (SGG), Eu8 Ga16 Ge30 (EGG), and Sr8 Ga16 Si30 (SGS) single crystals, performed at a high-energy facility. Unexpected features evidencing the different shift for the 2a and 6d sites between Ba4d and Sr3d are observed for BGG and SGG. The detailed analyses including theoretical support by first-principles band-structure calculations lead to the surprising conclusion that the component distributions of the larger tetrakaidecahedral cage are different depending on the endohedral atoms, which is in contrast to the past consensus that BGG and SGG have the same framework structure. The differences are further supported by analysis of the Ga3d core levels. This may suggest thorough reconsiderations on earlier interpretations of experimental data.
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U2 - 10.1103/PhysRevB.78.085203
DO - 10.1103/PhysRevB.78.085203
M3 - Article
AN - SCOPUS:49649107181
VL - 78
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
SN - 1098-0121
IS - 8
M1 - 085203
ER -