Ferroelectric properties of electron-irradiated copolymers of vinylidenefluoride and trifluoroethylene

Based on copolymer's dielectric characteristics versus temperature at multifrequency and hysteresis loops, ferroelectric properties of irradiated vinylidene fluoride and trifluoroethylene copolymer have been studied. Curie points of the copolymers are shifted to low temperatures and they decrease largely with irradiation dose increasing. The coercive field and remanent polarization both decrease with the increasing of irradiation dose, and the hysteresis loops become slimmer. These phenomena suggest that the normal ferroelectric copolymer is transformed into a relaxor ferroelectric by electron irradiation. Ferroelectric relaxation becomes more obvious at high dose irradiation. The relaxation mechanism is discussed and the relationships between ferroelectric relaxation and electron irradiation doses are also investigated in this paper.