TY - JOUR
T1 - Sodium trimer ordering on a NaxCoO2 surface
AU - Pai, Woei Wu
AU - Huang, S. H.
AU - Meng, Ying S.
AU - Chao, Y. C.
AU - Lin, C. H.
AU - Liu, H. L.
AU - Chou, F. C.
PY - 2008/5/21
Y1 - 2008/5/21
N2 - Sodium ion ordering on an in situ cleaved NaxCoO2 (x=0.84) surface has been studied by ultrahigh vacuum scanning tunneling microscopy at room temperature. Three main phases, with p(3×3), (7×7), and (2 3×2 3) hexagonal unit cells and a surface Na concentration of 1/3, 3/7, 1/2, respectively, were identified. One surprising finding is that Na trimers act as the basic building blocks that order in long range. The stability of Na trimers is attributed to the increased Na coordination with oxygen as indicated by ab initio calculations, and possibly at finite temperature by configuration entropy.
AB - Sodium ion ordering on an in situ cleaved NaxCoO2 (x=0.84) surface has been studied by ultrahigh vacuum scanning tunneling microscopy at room temperature. Three main phases, with p(3×3), (7×7), and (2 3×2 3) hexagonal unit cells and a surface Na concentration of 1/3, 3/7, 1/2, respectively, were identified. One surprising finding is that Na trimers act as the basic building blocks that order in long range. The stability of Na trimers is attributed to the increased Na coordination with oxygen as indicated by ab initio calculations, and possibly at finite temperature by configuration entropy.
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U2 - 10.1103/PhysRevLett.100.206404
DO - 10.1103/PhysRevLett.100.206404
M3 - Article
AN - SCOPUS:44249102325
SN - 0031-9007
VL - 100
JO - Physical Review Letters
JF - Physical Review Letters
IS - 20
M1 - 206404
ER -