CRYSTAL-STRUCTURE AND PARAMAGNETIC BEHAVIOR OF EPSILON-WO3-X

The crystal structure of the lowest-temperature E-phase of WO3 has bee n determined as a function of temperature by neutron powder diffractio n. The diffraction measurements show that there are no additional phas es at low temperatures. Magnetic measurements suggest that no supercon ductivity exists at temperatures as low as 9 x 10(-5) K, but instead, an increase of the magnetic susceptibility according to a paramagnetic Curie law was found. This observation indicates that unpaired carrier s persist in the sample, after cooling to very low temperatures.