Sol–gel synthesized semiconducting LaCo0.8Fe0.2O3-based powder for thick film NH3 gas sensor

Perovskite type LaCoxFe1−xO3 nanoparticles was synthesized by a sol–gel citrate method. The structural, electrical and sensing characteristics of the LaCoxFe1−xO3 system were investigated. The structural characteristics were performed by using X-ray diffraction (XRD) and transmission electron microscopy (TEM) to examine the phase and morphology of the resultant powder. The XRD pattern shows nanocrystalline solid solution of LaCoxFe1−xO3 with perovskite phase. Electrical properties of synthesized nanoparticles are studied by DC conductivity measurement. The sensor shows high response towards ammonia gas in spite of other reducing gases when x = 0.8. The effect of 0.3 wt.% Pd-doped LaCo0.8Fe0.2O3 on the response and a recovery time was also addressed.