Evidence of large-angle reorientation in supercooledo-terphenyl

Summary We study the reorientation process of a paramagnetic radical dissolved in supercooledo-terphenyl around and belowT _g via the Electron Spin Resonance spectroscopy. The experimental results are at variance with the hypothesis of diffusive reorientation of the radical. Instead, the ESR lineshapes are fairly well reproduced by assuming that the radical reorientates via large angular jumps with a width Δϕ=80° _−5° ^+10° . The results are compared with previous²H NMR studies. Paper presented at the I International Conference on Scaling Concepts and Complex Fluids, Copanello, Italy, July 4–8, 1994.