High-Resolution Photoemission Study of NaV₂O₄

抄録

We report high-resolution photoemission spectroscopy (PES) of quasi one-dimensional (1D) metal NaV₂O₄. We found that the valence band consists of well-separated two main bands; one originates in the V 3d states located around the Fermi level (E_F) and the other is due to the O 2p states situated far away from E_F in qualitatively good agreement with the band calculation. The PES spectrum near E_F shows a power-law behavior characteristic of quasi-1D materials. The anomalous exponent α shows a considerable temperature dependence, in particular around the magnetic transition temperature. The temperature dependence of α is also consistent with the variation of the transport anisotropy with temperature. These results suggest a close relationship between the electronic structure near E_F and the magnetic order and/or the dimensional crossover.