Electronic Structure near the Fermi Surface in the Quasi-One-Dimensional Conductor Li0.9Mo6O17

The electronic properties of the quasi-one-dimensional (1D) oxide conductor Li{sub 0.9}Mo {sub 6}O{sub 17} have been investigated using high-momentum and energy resolution photoelectron spectroscopy at temperatures above and below the metal-semiconductor transition temperature. Considerable spectral intensity at the Fermi energy (E{sub F}) is observed at room temperature, and a sharp feature corresponding to a band crossing E{sub F} is clearly resolved for states along the quasi-1D axis. Below the metal-semiconductor transition at 24thinspthinspK, a gap is clearly observed to open at E{sub F} . Our data do not support the assertion that the low energy excitations of electrons in Li{sub 0.9}Mo {sub 6}O{sub 17} should be described in a Luttinger liquid model. {copyright} {ital 1999} {ital The American Physical Society }