title: Correlation between primary and secondary Johari-Goldstein relaxations in supercooled liquids: invariance to changes in thermodynamic conditions.
abstract: The primary alpha and the secondary Johari-Goldstein (JG) beta relaxations of supercooled glass-forming neat epoxy resin and 2-picoline in mixture with tristyrene are monitored by broadband dielectric relaxation spectroscopy at ambient pressure and elevated pressures. For different combinations of pressure and temperature that maintain the alpha-relaxation time constant, the frequency dispersion of the alpha relaxation is unchanged, as previously found in other glass-formers, but remarkably the JG beta-relaxation time remains constant. This is more clear evidence of a strong connection between the alpha- and JG beta-relaxation times, a fact that should be taken into account in the construction of a viable theory of glass transition.
authors.affiliation: Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland. michal.mierzwa@us.edu.pl
authors.forename: M
authors.initials: M
authors.lastname: Mierzwa
authors.forename: S
authors.initials: S
authors.lastname: Pawlus
authors.forename: M
authors.initials: M
authors.lastname: Paluch
authors.forename: E
authors.initials: E
authors.lastname: Kaminska
authors.forename: K L
authors.initials: KL
authors.lastname: Ngai