Dynamical heterogeneity in glassy n-butanol

The light-induced cis-trans isomerization of azo dye molecules (1-naphthyl-p-azomethoxybenzene) is used as a probe process for dynamical heterogeneity in glassy n-butanol (T-g=114 K). The characteristic lifetime of heterogeneity is found to vary with temperature according to the Arrhenius law from 3 x 10(4) s at 100 K to 4 x 10(3) s at 110 K with the activation energy of 17 +/- 5 kJ/mole.