Effects of annealing conditions on ferroelectric nanomesa self-assembly

Abstract

We report the results of studies of the effects of annealing conditions on the morphology of ferroelectric nanomesas. The nanomesa patterns were fabricated by self-assembly from continuous ultra-thin Langmuir–Blodgett films of copolymers of vinylidene fluoride and trifluoroethylene. Annealing in the paraelectric phase induced surface reorganization into disc-shaped ferroelectric nanomesas approximately 9 nm thick and 100 nm in diameter. Several factors affect the nanomesa dimensions, such as polymer composition, substrate material, deposition conditions, and annealing temperature. The height and diameter of the nanomesas both increase with increasing annealing temperature. Annealing studies in the ferroelectric–paraelectric coexistence region show that only the paraelectric phase is mobile. From this we conclude that the paraelectric phase supports a kind of plastic crystalline flow connected with dynamic disorder of the polymer conformation.