Electrical properties of BaPb_1+x−y Sb _y O₃ ceramics derived from a modified sol-gel method

BaPbO₃ ceramics has attracted considerable interest due to the promising electrical applications. For the best control of the microstructure and phase, Sb-doped BaPbO₃ ceramics were prepared by a sol-gel route. Inorganic compounds were used as starting chemicals, citric acid and Ethylene diamine tetra-acetic acid (EDTA) as complex chelate agent, and distilled water as solvent. Experimental results demonstrate that the Sb-doped BaPbO₃ ceramics with homogeneous composition could be prepared by the method mentioned above. Influence of Pb/Ba ratio and Sb concentration on the room-temperature resistivity and the PTCR behavior of BaPb_1+x−y Sb _y O₃ (x = 0.0, 0.1, 0.2 and 0 ≤ y ≤ 0.2) compositions was investigated. The PTCR behavior was related to the Pb/Ba ratio and major compensating defect in BaPbO₃. The lowest electrical resistivity of Sb-doped BaPbO₃ was calculated to be 2.69 × 10⁻⁴ Ω·cm when the Sb concentration y = 12–13 mol%. The 0.5 mol% Sb-doped BaPbO₃ showed the best PTCR behavior, and its Curie temperature is about 850 °C.