TY - JOUR
T1 - Role of fragility in the formation of highly stable organic glasses
AU - Sepúlveda, A.
AU - Tylinski, M.
AU - Guiseppi-Elie, A.
AU - Richert, Ranko
AU - Ediger, M. D.
PY - 2014/7/23
Y1 - 2014/7/23
N2 - In situ dielectric spectroscopy has been used to characterize vapor-deposited glasses of methyl-m-toluate (MMT), an organic glass former with low fragility (m=60). Deposition near 0.84Tg produces glasses of very high kinetic stability; these materials are comparable in stability to the most stable glasses produced from more fragile glass formers. Highly stable glasses of MMT, when annealed above Tg, transform into the supercooled liquid by a heterogeneous mechanism. A constant velocity propagating front is initiated at the free surface and controls the transformation of thin films. The transition to a bulk-dominated transformation process occurs at 5μm, the largest length scale reported for any glass. Contrary to recent conclusions, we find that physical vapor deposition can form highly stable organic glasses across the entire range of liquid fragilities.
AB - In situ dielectric spectroscopy has been used to characterize vapor-deposited glasses of methyl-m-toluate (MMT), an organic glass former with low fragility (m=60). Deposition near 0.84Tg produces glasses of very high kinetic stability; these materials are comparable in stability to the most stable glasses produced from more fragile glass formers. Highly stable glasses of MMT, when annealed above Tg, transform into the supercooled liquid by a heterogeneous mechanism. A constant velocity propagating front is initiated at the free surface and controls the transformation of thin films. The transition to a bulk-dominated transformation process occurs at 5μm, the largest length scale reported for any glass. Contrary to recent conclusions, we find that physical vapor deposition can form highly stable organic glasses across the entire range of liquid fragilities.
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U2 - 10.1103/PhysRevLett.113.045901
DO - 10.1103/PhysRevLett.113.045901
M3 - Article
C2 - 25105633
AN - SCOPUS:84904988942
SN - 0031-9007
VL - 113
JO - Physical Review Letters
JF - Physical Review Letters
IS - 4
M1 - 045901
ER -