Abstract
Thick lamellar single crystals and large bulk single crystals are found to grow in films of vinylidene fluoride and trifluoroethylene copolymers when they are annealed at temperatures between the Curie point and melting point. The morphologies of these crystals are studied using SEM, TEM, and X-ray diffraction. The lamellar crystals are thick (0.1 µm) enough to be characterized as extended chain crystals. They are stacked together with their planes perpendicular to the film surface. The bulk single crystals exhibit various crystal habits with the maximum size 12 × 10 × 10 µm3. They are developed on the lamellar crystals from which the constituent molecules seem to be supplied. The growth of the crystals is discussed on the basis of the diffusive displacement of the molecules along the chain axis which becomes violent above the Curie temperature.