|Title||Surface Self-Diffusion of an Organic Glass|
|Publication Type||Journal Article|
|Year of Publication||2011|
|Authors||Zhu, L., C. W. Brian, S. F. Swallen, P. T. Straus, M. D. Ediger, and L. Yu|
|Journal||Physical Review Letters|
|Keywords||COEFFICIENTS, DYNAMICS, FILMS, INDOMETHACIN, MOBILITY, POLYMERS|
Surface self-diffusion has been measured for an organic glass for the first time. The flattening of 1000 nm surface gratings of liquid indomethacin occurs by viscous flow at 12 K or more above the glass transition temperature and by surface diffusion at lower temperatures. Surface diffusion is at least 10^6 times faster than bulk diffusion, indicating a highly mobile surface. Our data suggest that surface diffusion is the leading mechanism of surface evolution for organic glasses at micrometer to nanometer length scales.
|Alternate Journal||Phys. Rev. Lett.|