[10p-M116-1~22] 9.1 Dielectrics, ferroelectrics

[10p-M116-16] [Young Scientist Presentation Award Speech] Orientational Correlation between Ferroelectric Domain Walls and Crystallographic Axis in Organic Ferroelectric Thin Films

〇Yohei Uemura¹, Shunto Arai¹, Junya Tsutsumi², Satoshi Matsuoka¹, Reiji Kumai³, Sachio Horiuchi², Tatsuo Hasegawa^1,2 (1.U. Tokyo, 2.AIST, 3.KEK)

Keywords:organic ferroelectrics, ferroelectric domain, domain observation technique of ferroelectrics

For the device application of proton-transfer type organic ferroelectrics, which have small coercive electric field, it is essential to understand the motion of ferroelectric domain walls in thin films. We have developed a new optical technique to visualize ferroelectric domains named “ferroelectrics field modulation imaging (FFMI)”, which utilizes the electro-optic effect. In contrast to piezoresponse force microscopy (PFM), FFMI can probe the domain structure in depth direction because FFMI detect the transmitted light. In this study, the three-dimensional structure of domain walls was investigated by the comparison between FFMI and PFM. In addition, crystal orientation was determined in order to observe the orientational correlation between ferroelectric domain walls and crystallographic axis. The result reveals that the domain walls tend to be parallel to spontaneous polarization. Thus, the domain walls are electrically neutral, which is energetically favorable from the point of view of electrostatic energy.