  Nanoparticles grown in a plasma are used to visualize the process of film
deposition in a pulsed radio-frequency (rf) atmospheric pressure glow
discharge. Modulating the plasma makes it possible to successfully prepare
porous TiO2 films. We study the trapping of the particles in the sheath during
the plasma-on phase and compare it with numerical simulations. During the
plasma-off phase, the particles are driven to the substrate by the electric
field generated by residual ions, leading to the formation of porous TiO2 film.
Using video microscopy, the collective dynamics of particles in the whole
process is revealed at the most fundamental "kinetic" level.
