Electrical Properties of a One-dimensional Conductor, NaxV2O5

The resistivity measurement, DTA analysis, refinement of the crystal structure, and examination of the X-ray diffuse scattering have been carried out on the β-phase of the sodium vanadium bronze. A resistivity minimum was observed around 200 K. The peak position of the logarithmic derivative of the resistance and an anomaly in the DTA curvature indicate that a metal-insulator transition occurs at about 130 K. The X-ray diffuse scattering shows a tendency of the sodium atoms toward cluster formation. It is concluded that the β-phase of sodium vanadium bronze is neither a simple one-dimensional metal nor a simple semiconductor, but can be-have partly as a one-dimensional metal and partly as an anisotropic semiconductor.