title: XANES study of charge ordering on the spin-Peierls phase transition of alpha'-NAV2O5.
abstract: 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.
authors.affiliation: Graduate School of Science and Technology, Chiba University, Yayoi, Inage, Japan. syobu@rism.tohoku.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Shobu
authors.forename: Y
authors.initials: Y
authors.lastname: Noda
authors.forename: E
authors.initials: E
authors.lastname: Ninomiya
authors.forename: H
authors.initials: H
authors.lastname: Sawa
authors.forename: S
authors.initials: S
authors.lastname: Nagamatsu
authors.forename: T
authors.initials: T
authors.lastname: Fujikawa
authors.forename: Y
authors.initials: Y
authors.lastname: Ueda
authors.forename: M
authors.initials: M
authors.lastname: Isobe
authors.forename: N
authors.initials: N
authors.lastname: Ikeda
authors.forename: T
authors.initials: T
authors.lastname: Uruga