Dynamics of glass-forming liquids. VI. Dielectric relaxation study of neat decahydro-naphthalene

We have measured the dielectric relaxation of neat cis/trans-decahydro-naphthalene (decalin) in its supercooled regime as a function of temperature. The fragility of this nonaromatic molecular glass former is extremely high, m=147, and the distribution of relaxation times in terms of the stretching exponent is accordingly wide, betaapproximate to0.33. Regarding molecular organic liquids, such high fragilities have been observed before only for aromatic systems, e.g., toluene and triphenyl-phosphite. It turns out that the structural relaxation of neat decaline differs significantly from that of the 17.2 mol % chlorobenzene doped counterpart reported earlier. (C) 2002 American Institute of Physics.