Abstract
Thermal and structural experiments on thin free-standing liquid-crystal films of n-heptyl-4-n-pentyloxybiphenyl-4-carboxylate have revealed the existence of a surface-freezing phenomenon, in which surface crystal-E layers coexist with a hexatic-B interior. The crystal-E surface is typically found by electron diffraction to exist in twin domains in which the orientation of the orthorhombic lattice is rotated by 2°3°with respect to that of the underlying hexatic-B bond-orientational axes. It is shown theoretically that such a rotation minimizes the energy of the strain by the two incommensurate types of structural order, analogous to the Novaco-McTague theory, which applies to the orientational epitaxy of a crystalline overlayer on an incommensurate crystalline substrate.
Original language | English (US) |
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Pages (from-to) | R7891-R7893 |
Journal | Physical Review A |
Volume | 44 |
Issue number | 12 |
DOIs | |
State | Published - 1991 |
Bibliographical note
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