Pretilted nematic layers of 5CB on PTFE treated glass supports

Planar nematic layers of 5CB oriented by 'sliding on' nanolayers of PTFE were studied by electrooptic methods. Deposited layers have been characterized by AFM and polarizing uideomicroscopy. By using a drop method it was established that the preferred director alignment is tilted opposite to the sliding direction. In some of these samples an unusual modulated domain pattern after switching off a prolonged a.c. excitation was observed for the first time. A possible relation between the domain origin and loosely deposited PTFE layers was suggested.