Surface twist disclination in nematics on ferroelectric TGS

Abstract

1) The domains of different contrast in NLC over the ferroelectric domains of TGS are encircled by the surface twist disclination lines with the strengthsσ1=58/360 andσ2=1/2-58/360. 2) During the phase transition of TGS from ferroelectric to paralelectric state the surface of TGS starts to be uniform and thus theσ1-line disappears and theσ2-line transforms to theπ-twist disclination line. 3) The value of the surface anchoring energy for both ferroelectric and paraelectric state of TGS can be estimated to be within the limits 10−6−7×10−7 J/m2.