INFRARED REFLECTIVITY STUDIES ON QUASI-2 DIMENSIONAL MOLYBDENUM OXIDES MO4O11

Infrared reflectivity of the quasi-two dimensional oxides eta-Mo4O11 and gamma-Mo4O11, has been investigated on single crystals, using polarized light, in the range of 300-4000 cm-1, at room temperature and in the charge density wave (CDW) state. At 300 K, the anisotropy of the reflectivity emphasizes the anisotropy of the conduction electron gas, with a metallic behavior within the (100) plane and a semiconducting behavior in the [100] direction. In this direction, the IR reflectivity is fitted with the phonon oscillators. At low temperature, the decrease of the IR reflectivity is consistent with the loss of carriers, induced by the CDW gap opening.