آرام سازی نوری و دی الکتریک مواد ترکیبی ارگانیک-هیبریدی بر پایه گذار بر روی فلز

The [(CH3)3NH]CdCl3 (1) and [N(CH3)3H]CoCl3·2H2O (2) compounds were obtained by slow evaporation at room temperature and characterized by X-ray powder diffraction patterns. These compounds were crystallized in the orthorhombic system, in Pbnm and Pnma space groups, respectively. The optical properties were measured by means UV–Vis absorption spectrometry in order to deduce the absorption coefficient α and optical band gap Eg. The Tauc model was used to determine the optical gap energy of the synthesized compounds 1 and 2. Data analysis revealed the existence of two optical transition mechanisms. The calculated values of the direct and indirect band gaps (Egd, Egi) for both samples were estimated between 5.41 and 5.30 eV for compound 1; and between 4.02 and 3.82 eV for compound 2. The dependence of the optical constants, the refractive index (n) and the extinction coefficient (k) of compounds 1 and 2 were calculated and the results discussed. The normal dispersion of refractive index of the samples was described using the Wemple–DiDomenico single oscillator method. The optical dispersion parameters Eo and Ed were determined according to the above oscillator method. We employed dielectric spectroscopy to investigate the dipolar dynamics in the both compound. The evolution of the dielectric loss as a function of frequency showed a distribution of relaxation times; which is probably due to the reorientational dynamics of alkyl chains in compound 1, analyzed with the Cole–Cole formalism. Various relaxation processes and their locations of compound 2 were analyzed according to the fitted data of the Havriliak–Negami (HN) function. Different relaxation processes were found to belong to non-debye relaxation. The dielectric constants were composed of two dielectric relaxation peaks, DC conduction and electrode polarization (EP) effect. The determined values of relaxation time are characteristic of the co-operative reorientation of the trimethylammonium cation.