Nonelectrical Poling in Ferroelectric Polycyanophenylenesulfides

A new poling method utilizing the cooperativity of cyanophenyl groups was proposed in ferroelectric polycyanophenylenesulfides (PCPS). The method called “surface energy poling” takes advantage of the energy difference in the top and bottom surfaces of a polar aggregate to form a remanent polarization. The PCPS film sandwiched between a metal with higher surface energy and polytetrafluoroethylene with lower surface energy was heated to T cp [1.2× T g (glass transition temperature)] and cooled slowly to room temperature. The remanent polarization that gives a pyroelectric constant of 10 µC/m 2 K and an electrooptic coefficient ( r 33 ) of 80 pm/V in the resulting film was realized.