Dynamics of glass-forming liquids.: VII.: Dielectric relaxation of supercooled tris-naphthylbenzene, squalane, and decahydroisoquinoline

We have measured the dielectric relaxation of several molecular organic supercooled liquids, alphaalphabeta-tris-naphthylbenzene (C36H24 and C36H10D14), squalane, and decahydroisoquinoline. The dynamics is studied in the frequency range 10(-2)-10(7) Hz, equivalent to temperatures between T-g and approximately 1.2xT(g). For the very low dielectric loss materials, a resolution of tan deltaapproximate to3x10(-5) is required in order to observe the details of the relaxation behavior. Characteristic quantities like fragility, relaxation time dispersion, time-temperature superposition, and the slow Johari-Goldstein type beta relaxation are among the properties discussed. (C) 2003 American Institute of Physics.