Anisotropic magnetoresistance of (TMTSF)2CIO4 in the metallc and SDW state

The transverse magnetoresistance (Δρgr) of (TMTSF)2ClO4 has been measured at ambient pressure in the temperature range from 0.5K to 4.2K for various cooling rates through the ClO4− anion ordering temperature (~24K). The transverse magnetoresistance is highly anisotropic for the field orientations in the plane perpendicular to the highly conducting a-axis. For temperatures below the metal-SDW transition in the quenched state, the magnetoresistance has maximum when the magnetic field is parallel to the lowest conductivity direction c∗ and its value is temperature independent. In the metallic (relaxed) phase, magnetoresistance maximum occurs for a field direction b′ in the field of 1.2T. With decreasing temperature, the value of b′-axis magnetoresistance continuously increases in the metallic phase.