TWO-DIMENSIONAL ELECTRONIC-PROPERTIES OF THE PURPLE POTASSIUM MOLYBDENUM BRONZE K0.9MO6O17

The electrical and magnetic properties between 2 K and 300 K, the low temperature specific heat and the crystal structure at 300 K are studied on single crystals of K//0//. //9Mo//6O//1//7 grown by the electrolytic reduction technique. K//0//. //9Mo//6O//1//7 is found to be a quasi two-dimensional metal; this is consistent with the structural data. The transition which takes place below 120 K is due to the partial opening of a gap at the Fermi surface, possibly related to the onset of a charge density wave.