Preparation of Sr-Doped Lafeo3 by Thermal Decomposition of Metal Organic Complex and their Gas-Sensing Properties

Abstract

Sr-doped LaFeO3 powders, named herein as La1-xSrxFeO3 (x represents the Sr-doping molar ratio with respect to La used at the starting point of the synthesis), were prepared by thermal decomposition of metal organic complexes. The obtained products show the characteristic orthorhombic structure of La1-xSrxFeO3 perovskite with grain sizes of ~2-5 μm. SEM imagesindicate that the growth of the grain is restrained with the increasing concentration of Sr (II) dopant and leads to the small particle size. The specific surface area of 8-12 m2/g was observed, and the variation of specific surface area is related to the different particle size. The sensitivity of La1- xSrxFeO3 films was tested for ethanol, acetone, methane and hydrogen at different concentrations and temperatures. The films were found to be selective and applicable for detecting ethanol gas. The highest response to 1000 ppm ethanol is ~31.8 at 350°C for the La0.5Sr0.5FeO3. Keywords: LaFeO3; Ethanol sensing, gas sensor; Metal-organic complex; La1-xSrxFeO3 thick film;