Synthesis, Characterization and Humidity Sensing Application of Perovskite LaFeO3

In the past few decades, lanthanum ferrite has grown the importance in research due to attractive LPG/ humidity sensing and photolytic applications. In present study, the perovskite lanthanum ferrite was synthesized via solid state reaction route for three compositions by varying La/Fe ratio. The synthesized samples were characterized by Fourier transform spectroscopy, UV-vis spectroscopy, X-ray diffraction and scanning electron microscopy. The crystallization of lanthanum ferrite is confirmed by X-ray diffraction studies. The average crystallite size was found to be 45-50 nm. Surface morphological study of synthesized samples shows the uniform growth of the particles and grain which leaves the pores during its inter connection. These pores act as gas adsorption sites. The optical band gap of synthesized LaFeO3 samples were found to be 3.91-4.03 eV. Prepared samples were investigated for humidity sensing application. The average sensitivity of synthesized lanthanum ferrite samples was found to be 10.18-11.46 MΩ/%RH. The average sensitivity varies with the composition of the sample.