کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5390075 | 1505083 | 2008 | 4 صفحه PDF | دانلود رایگان |

The acoustic waves propagating along the direction perpendicular to the (1Â 0Â 0) cleavage plane of aspirin crystal were investigated using micro-Brillouin spectroscopy from which C11, C55 and C66 were obtained. The temperature dependence of the longitudinal acoustic waves could be explained by normal anharmonic lattice models, while the transverse acoustic waves showed an abnormal increase in the hypersonic attenuation at low temperatures indicating their coupling to local remnant dynamics. The sound velocity as well as the attenuation of the longitudinal acoustic waves of glassy aspirin showed a substantial change at â¼235Â K confirming a transition from glassy to supercooled liquid state in vitreous aspirin.
Brillouin scattering spectrum of aspirin in its crystal and glassy phases.
Journal: Chemical Physics Letters - Volume 465, Issues 1â3, 3 November 2008, Pages 36-39