抄録
In this work, the ferroelectric behavior in an orthogonal ferroelectric SmAdPF phase composed of an unsymmetric bent-core molecule with a carbosilane terminal group was studied. The ferroelectricity of the SmAdPF phase was unambiguously confirmed by electro-optical study, optical second-harmonic generation (SHG) and high dielectric strength. The long-range polar order is a consequence of weakened interlayer coupling due to the formation of carbosilane sublayers, which allows for the parallel order of dipole moments of bent-core molecules in the neighboring layers. The polar surface anchoring also brings about strongly thickness dependent polar fluctuations, as proved by the dielectric measurements (Goldstone-like mode). Theory developed qualitatively explains the experimental results, supporting the polarization splay model proposed.
