A COMPUTER SIMULATION INVESTIGATION OF THE FREEDERICKSZ TRANSITION FOR THE NEMATIC PHASE OF A GAY-BERNE MESOGEN

We present the first computer simulation study of the Freedericksz transition in a nematic phase using a Gay-Berne model mesogen, in which the constituent molecules can both rotate and translate freely. The behaviour and structure of the nematic obtained from the simulation for the Freedericksz transition are compared with those for real nematogens. The twist elastic constant has been estimated directly from the threshold field and found to be significantly larger than for real systems although comparable to another Gay-Berne nematogen. The molecules in the middle of the cell are observed to have a biaxial order in the vicinity of the Freedericksz transition. Those molecules adjacent to the surface are found to be unpinned in a discontinuous transition at a field significantly larger than the threshold field for the Freedericksz transition.