We reviewed pressure-temperature phase diagram of the title compound by electrical resistivity measurement. We observed the clear evidence of the (0,1/2,1/2) anion ordering transition in resistivity by an abrupt decrease below the transition reminiscent to the one in (TMTSF)2ClO4. Successive anion ordering transitions are clearly confirmed in the intermediate pressure range. Overall characteristics of our phase diagram agree with that determined by X-ray scattering.
- Organic superconductors