title: Nonelectrical poling in ferroelectric polythioureas.
abstract: A new poling method utilizing the cooperativity and strong hydrogen bonding force of thiourea groups is proposed in ferroelectric polythioureas [poly(octamethylene thiourea) and poly(nonamethyleno thiourea)]. The method, which is named "surface energy poling," takes advantage of the surface energy difference of the polar amorphous material to form remanent polarization. A polythiourea film sandwiched between a metal with higher surface energy and polytetrafluoroethylenes with lower surface energy was heated up to T/sub c/ [1.15/spl times/T/sub g/ (glass transition temperature)] and cooled slowly to room temperature. The resulting film showed a pyroelectric constant of 10 /spl mu//m/sup 2/K, giving evidence of remanent polarization. This method is similar to the orientation process in liquid crystal devices.
authors.affiliation: Fac. of Eng., Shizuoka Univ., Hamamatsu, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tasaka
authors.forename: H
authors.initials: H
authors.lastname: Ohta
authors.forename: N
authors.initials: N
authors.lastname: Inagaki