Acta Phys. -Chim. Sin. ›› 2004, Vol. 20 ›› Issue (10): 1253-1257.doi: 10.3866/PKU.WHXB20041018

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Thickness Dependence of Ferroelectricity in Hemic yanine Langmuir-Blodgett Multilayer Films

Li Shu-Hong;Ma Shi-Hong;Li Bo;Sun Jing-Lan;Wang Gen-Shui;Meng Xiang-Jian;Chu Jun-Hao;Wang Wen-Cheng   

  1. Department of Optical Science and Engineering, State Key Laboratory for Advanced Photonic Materials and Devices, Fudan University, Shanghai 200433; 1Department of Physics, State Key Laboratory for Advanced Photonic Materials and Devices, Fudan University, Shanghai 200433, National Laboratory for Infrared Physics, Chinese Academy of Sciences, Shanghai 200083
  • Received:2004-03-15 Revised:2004-05-24 Published:2004-10-15
  • Contact: Ma Shi-Hong E-mail:shma@fudan.edu.cn

Abstract: Typical ferroelectricity in Langmuir-Blodgett multilayers prepared from hemicyanine dyes has been demonstrated by observed ferroelectric hysteresis loop. Their ferroelectric properties are found to be thickness dependent. The coercive field decreased with increasing film thickness monotonously and may be approximated by a power law Ec∝N-4/3 in the range from 30 to 200 nm, which is coincident with other conventional ferroelectric materials. The optimum thickness of hemicyanine LB multiplayer is about 60 nm and their optimum value as ferroelectric storage-devices has the same order of magnitude as P(VdF-TrEE)(n :n=70 :30).

Key words: Langmuir-Blodgett films, Ferroelectricity, Hysteresis loop, Coercive field, Optimum value