eng Oriental Scientific Publishing Company Material Science Research India 0973-3469 2017-06-25 14 1 31 36 5379 article Rami A. Omari 1 Gilbert Ayuk 2 Department of physics, Al al-Bayt University, P.O.BOX 130040, Mafraq 25113, Jordan. Fulton-Montgomery Community College, 2805 State Highway 67, Johnstown, NY 12095 . The glass transition temperature and the surface dynamics of poly (butyl methacrylate) (PBMA) films have been studied using a phase-modulated ellipsometer equipped with a home-built sample cell with temperature controller. Experiments were performed for a range of temperatures, both above and below the glass transition temperature (Tg). In our study the glass transition temperature was obtained by plotting the ellipticity,  as a function of temperature using the data from the ellipsometric cooling scan. the correlation functions governing the fluctuations were calculated  at each temperature from the time-dependent fluctuations in film thickness as a function of temperature using ellipsometry data collected at 50 Hz frequency.  The results indicate that at temperatures well above Tg, the correlation functions obey a simple exponential decay. However, as Tg is approached, the correlation functions are best fitted with a stretched exponential relation, indicating a broad distribution of relaxation times. In addition, the temperature dependence of surface relaxation process has been found to be much weaker compared to the bulk relaxation. https://www.materialsciencejournal.org/vol14no1/a-study-of-supported-polyn-butyl-methacrylate-pbma-thin-polymer-films-near-the-glass-transition-temperature/ Correlation function Ellipsometer Glass transition temperature Stretched exponential relation Thin polymer films