Low Temperature Phase Diagram of (TMTTF)₂MF₆

Electron Spin Resonance: A Major Probe for Molecular Conductors

“…422,423 In a short period of time, many other materials were studied by this technique. 146,160,185,192,193,200,424 A quantitative agreement exists between the theory and the experiment. The experimental AFMR rotation patterns can be fitted to deduce the characteristic parameters introduced in section 3.1 (Ω -, Ω + , and r), and the position of the magnetic axes (Easy, Intermediate, and Hard axes).…”

“…159 Moreover, it should be mentioned that Spin-Peierls fluctuations sometimes exist above an antiferromagnetic ordering. This was suggested by EPR data on (TMTTF) 2 (SbF 6 ) 1-x (AsF 6 ) x alloys 155,160,161 and (TMTTF) 2 Br which lies at the borderline between the localized and itinerant regimes. 162 The presence of long-wavelength lattice fluctuations above the AF ordering has been recently revealed by spin-lattice relaxation time measurements with pulsed EPR.…”

“…However, characteristic rotation patterns were already obtained which unambiguously prove the antiferromagnetic nature of the ground state. Soon after these studies, AFMR was studied in sulfur analogues of the Bechgaard salts, (TMTTF) 2 Br, (TMTTF) 2 SbF 6 , and SCN. , AFMR appeared to be an excellent tool to prove unambiguously the ground-state nature of these organic conductors and to study its characteristics. , In a short period of time, many other materials were studied by this technique. ,,,,,, A quantitative agreement exists between the theory and the experiment. The experimental AFMR rotation patterns can be fitted to deduce the characteristic parameters introduced in section 3.1 (Ω - , Ω + , and r ), and the position of the magnetic axes (Easy, Intermediate, and Hard axes).…”

Magnetic phase transitions in bechgaard salts and related compounds: Electronic localisation and interchain couplings

“…In particular the evolution in the TMTTF series is rationalized noting an increase of #J going from the PF, to the AsF, and finally to the SbF, salt which has an A F ground state. In the same way the behaviour of the PF,/SbF, and AsF,/SbF, alloys in this series (Laversanne et al, 1986) can now be understood noting that #J should change noticeably among samples. The fact that localised samples remain paramagnetic at very low temperature is also a simple consequence of the possibility of a SP/AF crossover for any value of T,.…”