Equilibrium and non-equilibrium type beta-relaxations: D-sorbitol versus o-terphenyl

A previous observation, which indicated that the beta-relaxation intensity of o-terphenyl is sensitive to the thermal history, is substantiated by die lectric relaxation experiments. Unlike the beta-processes of other material s, only the quenched glassy state of o-terphenyl displays this secondary re laxation feature. The beta-intensity is observed to decay gradually upon an nealing and disappears altogether in the equilibrium liquid state at T > T- g. We compare the case of o-terphenyl with the concomitant signatures of D- sorbitol, which represents the more typical case of a glass-former which ex hibits the slow beta-process also in the liquid state including the alpha-b eta-merging scenario. We also present data of this alpha-beta-merging for D -sorbitol confined to pores of 5 nm diameter, indicating that no longer-ran ged correlations are involved in the secondary process.