LATTICE IMAGING OF FRICTION DEPOSITED PTFE FILMS

Highly oriented poly(tetrafluoroethylene) (PTFE) films were obtained b y sliding a bar of a commercial grade PTFE along a strip of mica at a temperature of 300 degrees C. High resolution transmission electron mi croscopy was used to image the <10(1)over bar 0> lattice planes of the hexagonal phase IV in suitably oriented regions of the sample, indica ting coherent order over distances of the order of at least 0.1 mu m b oth perpendicular and parallel to the chain axis.