Bond Orientational Order in a Single Smectic Layer and Hexatic Phase

3 Bond Orientational Order in a Single Smectic Layer and Hexatic Phase 

OrderAayer t3q e Liquid layer Hexatic layer Crystal layer 

Positional order Liquid-like Liquid like Quasi-long range 

A two-dimensional phase with a bond orientation order is called hexatic phase [12, 13]. It has six-fold symmetry Dsn and a new, two-compmient order parameter 

Depending on a material, single smectic monolayers can exist in two different modificati(His, liquid-like and hexatic like. Properties of these monolayers are shown in Table 5.1. Upon melting, a two-dimensional hexatic layer undergoes the transition into the liquid-like layer. It is spectacular that hexatic layers like liquid layers do not support the in-plane shear [14]. The layer can be sheared by as small force (stress) as is wished. 

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