Abstract
We have investigated the temperature, pressure, and field dependence of the spin density wave (SDW) transition in the organic superconductor (TMTSF(Formula presented)(Formula presented) and derived parameters for this transition. The SDW can be characterized by the degree to which the two Fermi surfaces couple or “nest” as measured by the imperfect nesting bandwidth (Formula presented). Perfect nesting (maximum (Formula presented)) occurs for (Formula presented)=0, and increasing pressure increases (Formula presented) and suppresses (Formula presented) to 0 K at a critical value (Formula presented). The increase of (Formula presented) with field has been shown to be orbitally driven, and the field dependence is nearly quadratic for fields in the c direction. We have made quantitative observations of the field dependence of (Formula presented) at ambient pressure to 29 T and under hydrostatic pressure to 8 T. From our measurements at ambient pressure we are able to extract (Formula presented) and (Formula presented) using mean field theory and observe (Formula presented)=12.1±0.1 K, (Formula presented)=4.5±0.3 K, and (Formula presented)=11.3±0.2 K. Under a hydrostatic pressure of 5.2±0.2 kbar, (Formula presented) increases to 11.0±0.3 K with (Formula presented) decreasing to 3.3±0.1 K. The high pressure results are consistent with the value of (Formula presented) from the ambient pressure measurements. We also observe no dependence of (Formula presented) with field in the a or b directions, in contrast to previous results.
Original language | English (US) |
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Pages (from-to) | 2727-2731 |
Number of pages | 5 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 53 |
Issue number | 5 |
DOIs | |
State | Published - 1996 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics