FERROELECTRIC POLYMER LANGMUIR FILMS

For the first time switchable ferroelectric Langmuir-Blodgett films we re prepared from the ferroelectric copolymer of vinylidene fluoride wi th trifluoroethylene P(VDF-TrFE). The film thickness was varied from 1 20 down to 2 monolayers of the copolymer, each monolayer being 5 Angst rom thick. The films show the first-order ferroelectric phase transiti on, switching the remanent polarization and pyroelectric effect. The r emanent polarization measured for a film of 175 Angstrom thick is of t he same order of magnitude as the value observed for the bulk of the s ame material P-s approximate to 0.1 C m(-2). The unusual temperature b ehaviour of the polarization leads to a rather high pyroelectric coeff icient at room temperature, of the order of 400 mu C m(-2) K-1.