Remanent polarization of evaporated films of vinylidene fluoride oligomers

A remanent polarization of 130+/-3 mc/m(2), large among the values reported for organic materials, and rectangular D-E hysteresis curves' were realized in synthesized vinylidene fluoride (VDF) oligomer [CF3(CH2CF2)(17)I] film evaporated onto a platinum surface around liquid nitrogen temperature. The results suggested that the VDF oligomer film has an extremely high crystallinity; and the electric dipoles arrange almost perfectly perpendicular to the film surface, and that a Lorentz local field factor of ferroelectric VDF oligomer crystals is nearly zero. Moreover, the obtained value of, the coercive field, which was larger than those of ferroelectric polymers, might be attributed to the steric hindrance arising from the existence of iodine atoms at the VDF oligomer chains. (C) 2003 American Institute of Physics.