Özet:

The theory predicts two-step melting in thin films, from crystal to a hexatic phase and then from hexatic to a liquid phase. Melting of LB films as a function of film thickness has been extensively studied in the literature. In literature distorted hexagonal lattice structure of Cd arachidate multilayer has been reported. Existence of a hexaticlike phase has been clearly evidenced in such studies. Further, existence of an intermediate smectic or nematic phase inserted between solid and hexatic phases in a system with a distorted hexagonal symmetry, as predicted by theory, has also been observed. Even in thick films of cadmium arachidate, low dimensionality effects have been observed in the surface region. Before melting transition, the distorted hexagonal lattice structure of CdA LB film transform to hexaticlike phase with increasing temperature. This hexaticlike phase is specified by a tilting of chains in vertical direction and a decrease in the in-plane distortion.

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