AR-SURFACES AND NEMATIC LIQUID-CRYSTAL ORIENTATION( BEAM SPUTTERING ON SOLID)

The molecular orientation of nematic 5CB on various solid substrates e roded obliquely by an Ar+ ion-beam has been studied experimentally. Th e sputtering on an isotropic substrate (normally evaporated SiO) resul ts in a nematic planar orientation along the projection of the local v elocity of the ion direction on the surface. When using an anisotropic substrate (obliquely evaporated SiO which gives planar orientation in absence of sputtering) we find a continuous twist of the resulting al ignment, from the initial planar orientation towards the beam track pr ojection. Although the geometry allows it, we do not observe any surfa ce orientation bistability.