Quasi-two-dimensional electronic properties of the sodium molybdenum bronze, Na 0.9Mo 6O 17

Four probe electrical resistivity measurements between 1.5 and 300 K were made on single crystals of the violet-red bronze Na _0.9Mo ₆O ₁₇ grown by a temperature gradient flux technique. The temperature variation of the resistivity shows metallic conductivity and highly anisotropic behavior similar to K _0.9Mo ₆O ₁₇ and Li _0.9Mo ₆O ₁₇. The room-temperature resistivity, measured in the direction parallel to the plate axis, is 3.0 × 10 ^-3 Ω cm and perpendicular to that axis it is 0.21 Ω cm. A transition observed at ∼88 K is possibly related to the onset of a charge density wave. The temperature variation of the susceptibility show Pauli paramagnetic behavior at high temperature, and highly anomalous behavior in the vicinity of the transition at low temperatures.