Zinc titanates nanopowders: synthesis and characterization
M.A. Gabal, Y.M. Al Angari
Abstract
Abstract Zinc titanates nanopowders viz.; Zn 2 TiO 4 , ZnTi 3 O 8 and ZnTiO 3 were synthesized through the thermal decomposition course of ZnC 2 O 4 .2H 2 O-TiO 2 precursors mixture (1:1 mole ratio), prepared via a new co-precipitation method up to 900 °C. Thermogravimetric measurement (TG) was utilized to characterize the precursors mixture decomposition while x-ray diffraction (XRD), Fourier transform infra-red (FT-IR) were used to characterize the decomposition products as well as the phase transitions at different temperatures. XRD revealed the starting of titanates formation at 700 °C via detecting Zn 2 TiO 4 along with ZnO and TiO 2 (anatase) diffraction peaks. By increasing the calcination temperature to 800 °C, the ZnO content vanished with the appearing of Zn 2 Ti 3 O 8 besides ZnTi 2 O 4 and impurities of TiO 2 (anatase). Finally at 900 °C, the Zn 2 Ti 3 O 8 content was decomposed into ZnTiO 3 . Nitrogen adsorption-desorption isotherm of the calcined precursors mixture at 900 °C indicated low specific surface area of 7.1 m 2 g −1 in accordance with the agglomeration nature estimated via transmission electron microscopy (TEM) study. The conductivity measurements showed semiconducting behavior of the prepared titanates with ferroelectric transition in the range 200 °C–308 °C. The obtained low dielectric value suggests the uses of present titanates as a co-fired ceramic or resonator ceramics.