Impedance spectroscopy study of TiO_2 addition on the ceramic matrix Na_2Nb_4O_(11)

摘要

In this paper a study of TiO_2 addition (0, 2, 5 and 10 wt%) and its effects in the impedance spectra of Na_2Nb_4O_(11) ceramic matrix was carried out. The structural, dielectric properties of the addition in the Na_2Nb_4O_(11) matrix were discussed. In the preliminary structural studies, X-ray diffractograms of the samples were recorded at room temperature with X-ray diffractometer with Cu-kα. The Rietveld refinement method was used and confirmed the monoclinic structure for pure sample. A study based on complex impedance spectroscopy was carried and the dielectric properties were obtained over a frequency range (100 Hz-1 MHz) in room temperature (300 K). In the dielectric analysis at 1 MHz was observed relative permittivity of 99.46 for pure sample and 84.37 to sample added with 5 wt% of TiO_2, those samples showed losses 3.55 × 10~(-2) and 9.22 × 10~(-2), respectively. In relation to relaxation phenomenon, Cole-Cole function was used for fitting pure and added samples data.