Materials Research Bulletin, Vol.34, No.14-15, 2167-2175, 1999
Design and fabrication of an automated technique: Measurement of spontaneous polarization in two new Schiff base ferroelectric liquid crystals
A technique for the measurement of spontaneous polarization (P-s) in ferroelectric liquid crystals (FLC's) is presented. Modification in the data acquisition part to measure the loop area of transient current due to the spontaneous polarization is described. Temperature dependence of the spontaneous polarization measured for the compound ZLI-3775 was found to agree with data provided by E. Merck Industrial Chemicals. The relative advantages and ease of operation in the present technique are discussed. This setup facilitates simultaneous measurement of spontaneous polarization and response times. Using the present setup, variation of the spontaneous polarization and response times with temperature are reported for two new Schiff base compounds, 4-undecyloxy benzylidene-4'-amino-2-methyl-butylcinamate (UOBAMBC) and 4-(2-chloro-propionyloxy) benzylindene-4'-amino-2-methylbutylcinamate (CPOBAMBC). The magnitude of P-s for CPOBAMBC is twice that of UOBAMBC.