High electric tunability of relaxor ferroelectric Langmuir–Blodgett terpolymer films

Poly(vinylidene fluoride-trifluoroethylene-chlorofloroethylene) terpolymer films have been fabricated on Al-coated polyimide substrates using the Langmuir–Blodgett (LB) technology. The electrical properties of the films have been investigated from 150 to 350 K. The temperature of the dielectric maximum and the measured frequency obeys the Vogel–Fulcher [J. Am. Ceram. Soc. 8, 339 (1925); Phys. Z. 22, 645 (1921)] law. The electric tunabilities of the films at room temperature are 42.6% and 80% under 50 and 240 MV/m, respectively. The reasons for the high tunability are discussed based on the special microstructure of the LB films.