Influence of Strontium on the Structural and Dielectric Properties of Hydrothermally Processed PbTiO3 Ceramic

摘要

Perovskite ceramic materials of the composition Pb_(1-x)Sr_xTiO3 (PS_xT) were prepared by hydrothermal process at a relatively low temperature. The solution of KOH favours the solubility of the precursors in solid state. Pressure and temperature are critical factors for the formation of pure perovskite PS_xT phase. The reaction mixture in stoichiometric amount is put in an autoclave and treated at 180 °C for 24 h. The powder obtained after grinding is treated at 400 °C for 4 h. X-ray diffraction shows that the compounds crystallize in a pure phase of perovskite type. SEM morphology indicates a homogeneous microstructure of the grains with the presence of pores. The impedance spectroscopy study in the frequency range (1 KHz - 2 MHz) confirms the insertion of stronium into the lead titanate matrix and highlights the strontium effect on the transition temperature (T_c) and the value of dielectric permittivity (ε_r).