Magnetotransport properties in purple bronze Li 0.9 Mo ₆ O ₁₇ single crystal

We have measured the resistivity along the a, b and c axes in Li0.9Mo6O17 single crystals. The anisotropy ratios ρc/ρa and ρc/ρb are presented, confirming the quasi–one-dimensionality of the compound. Both the sharp decrease in the anisotropy and the sharp increase in the Hall coefficient RH below a certain temperature (TM) indicate potential dimensional crossover. Negative magnetoresistances are observed with magnetic field (H) applied along the b-axis which could be ascribed to the suppression of dimensional crossover. In contrast, large positive magnetoresistance is observed with H applied along the a-axis and the c-axis. While the temperature-dependent resistivity anisotropy indicates dimensional crossover, we find no solid proof for the existence of CDW order by fitting the positive magnetoresistances.