title: Broadband dielectric spectroscopy and calorimetric investigations of D-lyxose.
abstract: Using broadband dielectric spectroscopy, we have studied different types of relaxation processes, namely, primary (α), secondary (β), and another sub-T(g) process called γ-process, in the supercooled state of D-lyxose, over a wide frequency (10(-2)-10(9) Hz) and temperature range (120-340 K). In addition, the same sample was analyzed by differential scanning calorimeter. The temperature dependence of the relaxation times as well as the dielectric strength of different processes has been critically examined. It has been observed that the slower secondary relaxation (designated as β-) process shifts to lower frequencies with increasing applied pressure, but not the faster one. This pressure dependence indicates that the observed slower secondary relaxation (β-) is Johari-Goldstein relaxation process and faster one (γ-process) is probably the rotation of hydroxymethyl (-CH(2)OH) side group attached to the sugar ring, that is, of intramolecular origin.
authors.affiliation: Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San-Sebastian, Spain. lokendrapratap_singh@ehu.es
authors.forename: Lokendra P
authors.initials: LP
authors.lastname: Singh
authors.forename: A
authors.initials: A
authors.lastname: Alegría
authors.forename: J
authors.initials: J
authors.lastname: Colmenero
mesh_terms: D002152:Calorimetry, Differential Scanning / Q000379:methods*; D058266:Dielectric Spectroscopy; D010429:Pentoses / Q000737:chemistry*; D013696:Temperature
chemical_list: D010429:Pentoses; C043333:lyxose