Abstract
In this work, we observed that the electrical properties of (Pb <sub>1-x</sub> Sr <sub>x</sub> )TiO <sub>3</sub> materials was significantly modified by the rate of cooling after sintering and the Pb-to-Sr ratio in the composition. Quench (> 1000°C/h) after sintering lowered the ρ <sub>max</sub> -value and increased the T <sub>max</sub> -value. Larger Pb-to-Sr ratio increased the Curie temperature and reduced the minimum and maximum resistivities of the samples. Increase the cooling rate reduced the (lnp)-T slope, that was ascribed to the decrease in the concentration of the excess cationic vacancies, the effective electron traps. The large negative temperature coefficient of resistivity (NTCR), can be attributed to the relative high energy levels of donors, that is, ε <sub>d</sub> ≅0.115 eV. The effective trap (ε <sub>I</sub> ) levels were estimated from the ρ <sub>max</sub> -T <sub>max</sub> of the materials to be ε <sub>I</sub> ≅0.542 eV. An energy diagram was proposed based on these observations.