Abstracto

Co: Fe2O3, CoxZn1-xFe2O4 Thin Films Grown by Chemical Spray Pyrolysis for Gas Sensor Application

Sevda S, Mutlu K, Omer C, Muhammet Y

Air pollution caused by toxic, flammable and explosive gases, detection of some hazardous gases is impossible for human, because some gases like CO and H2 are odourless and tasteless as well as colourless. Furthermore in some cases absolute gas concentrations is very low to be detected by human nose. Therefore development and fabrication of a device for early detection of certain flammable, explosive, and toxic gases are extremely necessary. For this purpose, different devices have been developed toward tract detection of such pollution gases. Consequently, the development of cheap and reliable devices for detection of gases is considered to be a significant goal in science. In this study, iron oxide compound triple and quaternary iron oxide compounds with Zn, Co metal dopants were grown by using Chemical Spray Pyrolysis (CSP) technique. The structural, optical, magnetic properties of Co:Fe2O3, CoxZn1-xFe2O4 compounds have been extensively investigated. XRD, Raman, SEMEDAX and AFM techniques have been used for structural analysis; Absorption technique has been used for optical properties; Vibrating sample magnetometer (VSM) techniques have been used for magnetic properties. XRD analysis of the growth films revealed that Co:Fe2O3 film has monoclinic, CoxZn1-xFe2O4 films have cubic polycrystalline structures. Gas sensors can be made from various materials depending on the purposes they serve. Regardless type of gas sensor, general requirements for a reliable gas sensor is high sensitivity, fast response, and good selectivity. It was found that Co:Fe2O3 and CoxZn1-xFe2O4 thin films operating at 200°C temperature could detect H2 at 100 ppm, 500 ppm and 1000 ppm concentration and at 600 s time with very high selectivity and sensitivity, with better stability.