title: Vapor-deposited glasses of methyl-m-toluate: How uniform is stable glass transformation?
abstract: AC chip nanocalorimetry is used to characterize vapor-deposited glasses of methyl-m-toluate (MMT). Physical vapor deposition can prepare MMT glasses that have lower heat capacity and significantly higher kinetic stability compared to liquid-cooled glasses. When heated, highly stable MMT glasses transform into the supercooled liquid via propagating fronts. We present the first quantitative analysis of the temporal and spatial uniformities of these transformation fronts. The front velocity varies by less than 4% over the duration of the transformation. For films 280 nm thick, the transformation rates at different spatial positions in the film differ by about 25%; this quantity may be related to spatially heterogeneous dynamics in the stable glass. Our characterization of the kinetic stability of MMT stable glasses extends previous dielectric experiments and is in excellent agreement with these results.
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: M
authors.initials: M
authors.lastname: Tylinski
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: A
authors.initials: A
authors.lastname: Sepúlveda
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: Diane M
authors.initials: DM
authors.lastname: Walters
authors.affiliation: Institute of Physics, University of Rostock, Wismarsche Str. 43-45, 18051 Rostock, Germany.
authors.forename: Y Z
authors.initials: YZ
authors.lastname: Chua
authors.affiliation: Institute of Physics, University of Rostock, Wismarsche Str. 43-45, 18051 Rostock, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Schick
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Ediger