Definition of smectic in English:



  • Denoting or involving a state of a liquid crystal in which the molecules are oriented in parallel and arranged in well-defined planes.

    Compare with nematic
    • ‘Hydrated phospholipids themselves are liquid-crystals, and in these multiple respects, their behavior resembles that of at least some other compounds that form smectic bulk phases.’
    • ‘A liquid crystal device is constituted by a chiral smectic liquid crystal to form a plurality of pixels.’
    • ‘From our measurements of fluctuations, we obtain the product of the bilayer bending modulus K C and the smectic compression modulus B.’
    • ‘Molecules in the smectic phase have orientational as well as a small amount of positional order.’
    • ‘Our results suggest that of the multiple structures which different monolayers form when supercompressed, pulmonary surfactant collapses by the same mechanism as other compounds that form smectic liquid-crystal bulk phases.’


  • A smectic substance.

    • ‘We find that the quantum smectics are rather different from the usual classical smectics in that the density correlations along the direction of the stripes manifest a Bragg-Glass type behaviour whereas those in the transverse direction are infra-red divergent.’
    • ‘I am using the hydrodynamic equations for smectics A to predict the results of these experiments, which are being performed by a colleague, Professor Stephen Kevan.’
    • ‘There also exists higher order smectics which form layers with positional ordering within the layers.’
    • ‘The winner, in a 1998 Physical Review Letters article co-authored with his wife Dr Mirjana Golubovic, has identified this phase as the very first realization of a new state of matter: the sliding phase of weakly coupled two-dimensional smectics of DNA molecules sandwiched between lipid membranes, that themselves form a layered three-dimensional lamellar phase.’
    • ‘We outline the possible experimental significance of our findings for the rheology of both aligned and polydomain smectics.’


Late 17th century: via Latin from Greek smēktikos ‘cleansing’ (because of the soaplike consistency).