  A growing body of experimental work indicates that physical vapor deposition
provides an effective route for preparation of stable glasses, whose properties
correspond in some cases to those expected for glasses that have been aged for
thousands of years. In this work, model binary glasses are prepared in a
process inspired by physical vapor deposition, in which particles are
sequentially added to the free surface of a growing film. The resulting glasses
are shown to be more stable than those prepared by gradual cooling from the
liquid phase. However, it is also shown that the composition of the resulting
glass, which is difficult to control in physical vapor deposition simulations
of thin films, plays a significant role on the physical characteristics of the
material. That composition dependence leads to a re- evaluation of previous
results from simulations of thinner films than those considered here, where the
equivalent age of the corresponding glasses was overestimated. The simulations
presented in this work, which correspond to films that are approximately 38
molecular diameters thick, also enable analysis of the devitrification
mechanism of vapor-deposited glasses. Consistent with experiments, it is found
that this mechanism consists of a mobility front that propagates from the free
interface into the interior of the films. Eliminating surface mobility
eliminates this route of transformation into the supercooled liquid.
