Local dielectric spectroscopy of near-surface glassy polymer dynamics

Autor:	Crider, P. S., Majewski, M. R., Zhang, Jingyun, Oukris, H., Israeloff, N. E.
Rok vydání:	2007
Předmět:	Condensed Matter - Soft Condensed Matter Condensed Matter - Disordered Systems and Neural Networks
Druh dokumentu:	Working Paper
DOI:	10.1063/1.2825301
Popis:	A non-contact scanning-probe-microscopy method was used to probe local near-surface dielectric susceptibility and dielectric relaxation in poly-vinyl-acetate (PVAc) near the glass transition. Dielectric spectra were measured from 10-4 Hz to 102 Hz as a function of temperature. The measurements probed a 20 nm thick layer below the free-surface of a bulk film. A small (4 K) reduction in glass transition temperature and moderate narrowing of the distribution of relaxation times was found. In contrast to results for ultra-thin-films confined on or between metallic electrodes, no reduction in the dielectric strength was found, inconsistent with the immobilization of slower modes. Comment: submitted
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/0707.1803 Zobrazit plný text záznamu View this record from Arxiv