  The propagation of a dissipative solitary wave across an interface is studied
in a binary complex plasma. The experiments were performed under microgravity
conditions in the PK-3 Plus Laboratory on board the International Space Station
using microparticles with diameters of 1.55 micrometre and 2.55 micrometre
immersed in a low-temperature plasma. The solitary wave was excited at the edge
of a particle-free region and propagated from the sub-cloud of small particles
into that of big particles. The interfacial effect was observed by measuring
the deceleration of particles in the wave crest. The results are compared with
a Langevin dynamics simulation, where the waves were excited by a gentle push
on the edge of the sub-cloud of small particles. Reflection of the wave at the
interface is induced by increasing the strength of the push. By tuning the ion
drag force exerted on big particles in the simulation, the effective width of
the interface is adjusted. We show that the strength of reflection increases
with narrower interfaces.
