Kityk, Andriy V.Andriy V.KitykWolff, MatthiasMatthiasWolffKnorr, KlausKlausKnorrMorineau, DenisDenisMorineauLefort, RonanRonanLefortHuber, PatrickPatrickHuber2022-06-072022-06-072008-10-02Physical Review Letters 101 (18): 187801 (2008-10-02)http://hdl.handle.net/11420/12822The optical birefringence of rod-like nematogens (7CB, 8CB), imbibed in parallel silica channels with 10 nm diameter and 300 micrometer length, is measured and compared to the thermotropic bulk behavior. The orientational order of the confined liquid crystals, quantified by the uniaxial nematic ordering parameter, evolves continuously between paranematic and nematic states, in contrast to the discontinuous isotropic-to-nematic bulk phase transitions. A Landau-de Gennes model reveals that the strength of the orientational ordering fields, imposed by the silica walls, is beyond a critical threshold, that separates discontinuous from continuous paranematic-to-nematic behavior. Quenched disorder effects, attributable to wall irregularities, leave the transition temperatures affected only marginally, despite the strong ordering fields in the channels.en1079-7114200818American Physical SocietyPhysics - Soft Condensed MatterPhysics - Soft Condensed MatterPhysics - Materials SciencePhysics - Statistical MechanicsPhysics - Chemical PhysicsPhysics - OpticsPhysikJournal Article10.1103/PhysRevLett.101.1878010810.0509v2Other