XANES study of charge ordering on the spin-Peierls phase transition of alpha'-NAV2O5.
alpha'-NaV2O5 transforms at Tc = 34K, and the origin of the phase transition seems to be caused by the charge order and spin-Peierls mechanism. However the experiments which reveal the existence of charge order are very little. We measured XANES of V atoms which relates to the valence of V. It was found that the valences of V atoms in NaV2O5 were V4.5+ in the high temperature phase by comparing pre-edge and XANES of NaV2O5 with that of LiV2O5 CaV2O5 and V2O5. The analysis of EXAFS also shows the environment of the V4.5+ state.
Shobu
T
T
Graduate School of Science and Technology, Chiba University, Yayoi, Inage, Japan. syobu@rism.tohoku.ac.jp
Noda
Y
Y
Ninomiya
E
E
Sawa
H
H
Nagamatsu
S
S
Fujikawa
T
T
Ueda
Y
Y
Isobe
M
M
Ikeda
N
N
Uruga
T
T