In-situ Transmittance Measurement of Polarization and Dielectric Relaxation Behaviors of LiNbO3 Ferroelectric Nanocrystal in Polycarbonate Matrix

LiNbO3/polycarbonate (LNO/PC) composite films with different concentration of LiNbO3 ferroelectric nanocrystals are prepared by spin coating method. The polarization and dielectric relaxation behaviors of LNO/PC composite films are characterized through in-situ transmission spectrum measurement. The LiNbO3 ferroelectric nanocrystals are prepared by hydrothermal method with rhombohedral structure and the average crystal size is about 50 nm. It’s found that 15%LNO/PC composite film has the largest orientation change with the ϕ value of 62% and slow dielectric relaxation, almost no decay after 6 h. Based on the literatures, we can proposed that the preferential orientation of LiNbO3 nanocrystals after poling is [001] direction. This suggests that in-situ transmittance measurement is a simple and effect way to evaluate the polarization and dielectric relaxation behaviors of ferroelectric nanocrystals/polymer systems.