STRUCTURES AND NONLINEAR-OPTICAL PROPERTIES OF 4-(N,N-DIMETHYLAMINO)-3-ACETAMIDONITROBENZENE FILMS PREPARED BY VAPOR-DEPOSITION

4-(N,N-dimethylamino)-3-acetamidonitrobenzene (DAN) was evaporated ont o a glass plate and a cleavage surface of KCl in vacuo. DAN films depo sited on the glass plate were composed of randomly oriented laminate c rystallites. The DAN film deposited on KCl substrate, on the other han d, was composed of tabular crystallites crossing orthogonally. The (00 1) plane of the DAN crystal lay parallel to the substrate surface, and its a axis oriented parallel to the [110] directions of the KCl subst rate. The second harmonic (SH) intensities of DAN films were measured. When the film deposited on KCl substrate was rotated around an axis c oinciding with the laser beam propagation direction, the SH intensitie s of the film changed periodically corresponding to the molecular conf iguration in the film. The biorientational order of DAN crystal observ ed by electron microscopy on KCl substrate was confirmed on a macrosco pic scale by second harmonic generation.