SECOND-HARMONIC GENERATION IN LANGMUIR-BLODGETT FILMS OF p-NITROANILINE DERIVATIVES

Mixed Langmuir-Blodgett films of N-stearoyl-p-nitroaniline and its homologous amphiphile, p-stearylaminophenylacetic acid, were investigated by optical second-harmonic generation (SHG). The second-harmonic (SH) intensity from Y-type films increased quadratically with increasing number of layers, and showed in-plane anisotropy to the dipping direction of the substrate. The SH intensity was changed by the dipping speed; this suggested a molecular orientation at the depositing site. Properties of thick LB films (thickness more than 1μm) were also investigated.