  In this work we present molecular dynamics simulations on the creep behavior
of $\rm Cu_{64}Zr_{36}$ metallic glass composites. Surprisingly, all composites
exhibit much higher creep rates than the homogeneous glass. The glass-crystal
interface can be viewed as a weak interphase, where the activation barrier of
shear transformation zones is lower than in the surrounding glass. We observe
that the creep behavior of the composites does not only depend on the interface
area but also on the orientation of the interface with respect to the loading
axis. We propose an explanation in terms of different mean Schmid factors of
the interfaces, with the amorphous interface regions acting as preferential
slip sites.
