Study of various relaxation processes and breakdown of Stokes-Einstein Debye relation in supercooled D-xylose

Abstract

Abstract Various relaxation procedure in the supercooled state of D-xylose have been investigated using dielectric spectroscopy over a wide frequency (1 mHz – 10 MHz) and temperature range (140-350 K). The main relaxation process (α) that is accountable for the glass transition phenomena, another secondary relaxation process is also visible below glass transition temperature. The attached hydroxymethyl (-CH2OH) side group to the sugar ring might be responsible for this process. In addition, we have applied Coupling model to find the location of intermolecular relaxation below the glass transition temperature (Tg). The dependence of various dielectric parameters viz. τα, τβ, τγ and τβ cm on temperature have been critically examined. The current experimental result shows that, log10 σdc vs. log10 τα dependence is nonlinear and hence can be described with the fractional Stokes-Einstein-Debye relation.