Selective and sensitive detection of CO gas by In2O3 thick film gas sensors

877-880This study aims to provide a better fundamental understanding of the gas sensing mechanism of In2O3 gas sensors. In the present work In2O3 powder has been derived by calcinations of In2S3 powder prepared by flux method. Thick film of In2O3 has been deposited utilizing a relatively simple and low cost screen printing technique and characterized by scanning electron microscopy and X-ray diffraction. In2O3 thick film exhibits much higher sensitivity to CO at 150 °C. The corresponding sensitivity is 10.2 with good selectivity, and the response and recovery times are 6 and 14 s, respectively. The results indicate that the In2O3 thick film can be used to fabricate high performance CO sensors

Selective and sensitive detection of CO gas by In2O3 thick film gas sensors

This study aims to provide a better fundamental understanding of the gas sensing mechanism of In2O3 gas sensors. In the present work In2O3 powder has been derived by calcinations of In2S3 powder prepared by flux method. Thick film of In2O3 has been deposited utilizing a relatively simple and low cost screen printing technique and characterized by scanning electron microscopy and X-ray diffraction. In2O3 thick film exhibits much higher sensitivity to CO at 150 °C. The corresponding sensitivity is 10.2 with good selectivity, and the response and recovery times are 6 and 14 s, respectively. The results indicate that the In2O3 thick film can be used to fabricate high performance CO sensors

Computational Modeling of Thermoelastic Problems of a Thin Annular Disc

The paper is concerned with the inverse unsteady-state problem of thermolelastic deformation of a thin annular disc in the plane state of stress. Homogeneous boundary conditions of the third kind are maintained on curved surfaces of the disc while on the lower plane surface the heat flux is maintained at u(r, t) = 0which a known function of r and t is. The flux is prescribed also on the plane z = which serves as the interior condition. A mathematically this problem of determining the temperature, displacement and stress functions of a thin annular disc is studied. The finite Marchi-Zgrablich and Laplace transform techniques are used to find the solutions of the inverse transient themoelastic problems of a thin annular disc. Key words: Boundary value problems; Thermoelasticity; Heat conductio

Studies on Gas Sensing Performance of Pure and Li2O-modified CdIn2O4Thick Film Resistors

The CdIn2O4 powder was derived from calcination of CdIn2S4 prepared by flux method. The material was confirmed by XRD. Using screen-printing technique, thick films of CdIn2O4 were prepared. The thick films were characterized by SEM, EDAX, TEP and flame photometry. The Li2O-modified CdIn2O4 films were obtained by dipping pure CdIn2O4 thick films in aqueous solution of lithium chloride for different intervals of time and fired at 500 0C for 2 h. Gas sensing properties of pure and Li2O-modified CdIn2O4 have been investigated. The Li2O-modified CdIn2O4 sensor was found to be highly sensitive to H2S, ethanol and LPG at different operating temperature. The gas response, selectivity, response time and recover time were studied and discussed

Synthesis of CdIn₂S₄ by flux method

321-324Stoichiometric and non-stoichiometric powders of CdIn₂S₄ have been synthesized by flux method. X-ray diffraction (XRD) studies reveal that CdIn₂S₄ powders are polycrystalline in nature with spinel cubic structure. Thick films of CdIn₂S₄ powders have been prepared using screen printing technique on glass substrates. The films are characterized by energy dispersive X-ray analysis (EDAX) for quantitative elemental analysis, scanning electron microscopy (SEM) for microstructural studies and optical absorption studies for determination of band gap energies. The optical band gap energy for stoichiometric film is observed to be 2.38 eV while for nonstoichiometric films, it increases as the Cd/In ratio increases