FERMI-SURFACE OF A QUASI-ONE-DIMENSIONAL OXIDE CONDUCTOR

We report the first determination of the Fermi surface for a quasi-one -dimensional oxide conductor, Li0.9Mo6O17. The Fermi surface has been measured within the cleavage plane of the crystal using high-resolutio n angle-resolved photoemission spectroscopy. The Fermi surface consist s of two parallel straight lines, separated by a nesting vector of app roximately 0.7 +/- 0.05 angstrom-1. A large density of states at E(F) is observed from the measured band dispersion, despite a low photoemis sion spectral intensity at E(F). The measured Fermi surface allows the prediction of the magnitude of the displacement vector associated wit h soft phonons and a postulated Peierls transition in Li0.9Mo6O17.