Moving grain boundary as a “comb” for surface particles

[Display omitted] •Ordering of surface particles by the moving grain boundary was detected in this study.•The ordering involves lining up of particles to form chains oriented along the direction of grain boundary motion.•The process takes place in the range of temperatures and compositions corresponding to the surface phase transition. Ordering of surface particles by the moving grain boundary was detected in this study. This beautiful effect was revealed in the previously studied Cu[Co] system. The ordering involves lining up of particles to form chains oriented along the direction of grain boundary motion. The process takes place in the range of temperatures and compositions corresponding to the surface phase transition. The morphology of thermally etched grooves allows one to estimate the speed of grain boundary ordering the surface particles.