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Surface modified nanocrystalline Cr2O3 based thick films for gas sensing
Authors: Chandak PM, Raghuwanshi FC, Kapse VD and Kalyamwar VS
Number of views: 589
Nanocrystalline Cr2O3 based thick films were successfully synthesized by co-precipitation method. As synthesized Cr2O3 were examined with the help of field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) spectroscopy. Structural behaviour of Cr2O3 nanoparticles was examined by X-ray diffraction (XRD). Thick films of pure Cr2O3 were prepared by screen-printing technique. The surfaces of these films were modified by dipping them into a 0.01M aqueous solution of ferric chloride (FeCl3) for different intervals of time, followed by firing at 550 0C for 30 min. Gas sensing properties of pure and modified Cr2O3 thick films were investigated. Fe2O3 modified Cr2O3 thick film dipped for 2 min showed higher gas response at 1000C. The effect of surface microstructure and Fe2O3 concentrations on the gas response, selectivity, response and recovery of the sensor in the presence of NH3, Cl2, LPG, CO2, H2S and C2H5OH gases ware studied and discussed. The quick response and fast recovery are the main features of this sensor.