The FSU acknowledges support from Grant No. NSFDMR 99-71474 and Grant No. IHRP 500/5031. A portion of this work was performed at the National High Magnetic Field Laboratory, which is supported by NSF Cooperative Agreement No. DMR-0084173 and by the state of Florida. Work at Argonne National Laboratory was supported by the Office of Basic Energy Science, Division of Materials Sciences, U.S. Department of Energy, under Grant No. W-31- 109-ENG-38. Research at Portland State University was supported by NSF Grant CHE-09904316.
Physical Review B
Electron paramagnetic resonance, Nuclear magnetic resonance, Charge transfer
The charge transfer salt β′-(ET)₂SF₅CF₂SO₃, which has previously been considered a spin-Peierls material with a TSP;33 K, is examined using high-resolution high-field sub-millimeter/millimeter wave electron spin resonance (ESR), and nuclear magnetic resonance (NMR) techniques. A peak in the nuclear spin-lattice relaxation behavior in fields of 8 T, accompanied by a broadening and paramagnetic shift of the resonance line, indicates a phase transition at Tc~20 K. A pronounced change in the high-field ESR excitation spectra at ~24 T, observed at Tc~20 K, may indicate the onset of antiferromagnetic (AFM) correlations of the low temperature phase in β′-(ET)₂SF₅CF₂SO₃. Peculiarities of the low-temperature magnetic and resonance properties of β′-(ET)₂SF₅CF₂SO₃ are discussed.
I.B. Ruetel, S.A. Svyagin, J.S. Brooks, J. Krzystek, P. Kuhns, A.P. Reyes, B.H. Ward, J.A. Schlueter, and R.W. Winter, High-Field Magnetic Resonant Properties of β'-(ET)2SF5CF2SO3, Phys. Rev. B, 67, 214417 (2003).