Growth, characterization and ultrasonic studies of n-Eicosane single crystals

Abstract

Ultrasonic measurements have been carried out on ultrapure (99.94 %) n-Eicosane single crystals at 35 Mz as a function of temperature from 233 K to the melting point, 313 K, both parallel and perpendicular to the alkane chain direction. The sound velocity was found to vary linearly with temperature up to 263 K. A departure from linearity over the remainder of the temperature range is interpreted as being due to the formation of molecular conformational defects within the crystal prior to the onset of rotator-phase behaviour at 306.3 K. The purity and structural purification of the crystals were defined, and the phase behaviour of this material was confirmed using differential scanning calorimetry.