Vibrational spectra, phase transition and nonlinear optical properties of anilinium perchlorate molecular-ionic solid
Résumé
Crystals of anilinium perchlorate, C6H5NH ClO 3 4 + −, were obtained by slow evaporation of an aqueous solution at room temperature. Powder Kurtz-Perry measurements were performed for the title material. The efficiency of second harmonic generation was estimated relative to KDP: d = 0.21dKDP. Room temperature powder infrared and Raman measurements for the title solid and its deuterated analogue were carried out. The vibrational spectra in the regions of the internal vibrations of the ions corroborate the X-ray data (reported by Paixão et al. [1]). Differential scanning measurements performed on the powder sample indicate a first order phase transition at about 220 K.Apossible mechanism of the phase transition is suggested in relation to disorder of the hydrogen atoms on nitrogen atoms (reported in [1]). The role of the aniline molecule in the second harmonic generation is discussed.