Magnetic field induced alignment of the director in a smectic A phase: surface effects

Deuterium NMR studies of the alignment by a magnetic field of the director in the smectic A phase of 4-octyl-4'-cyanobiphenyl have shown this to be a complex process. To explore the influence of the interaction between the sm ectic A phase and the surface of its container on the pathways available fo r director alignment we have investigated a droplet of this phase suspended in glycerol. The field induced alignment of the director in the droplet is found to be dramatically different, both quantitatively and qualitatively, to that found for the smectic A phase confined to a glass tube. (C) 2000 E lsevier Science B.V. All rights reserved.