Detection of liquefied petroleum gas below lowest explosion limit (LEL) using nanostructured hexagonal strontium ferrite thin film

Abstract The nano crystalline hexagonal strontium ferrite nanoparticles SrFe 12 O 19 were synthesized successfully by chemical co-precipitation method. Thin films of strontium ferrite were prepared on glass substrate and characterized by various techniques such as XRD, SEM, TEM, EDS, UV-spectroscopy and FTIR. XRD pattern revealed the phase transformation of M-type hexa-ferrite with the minimum crystallite size of 18 nm. Uniform macroporous surface structure of the film was exposed by SEM images. Existence of iron, strontium and oxygen in the material was confirmed by EDX. Optical characterization of the material was done by UV-Spectroscopy and band gap was found as 3.2 eV. The liquefied petroleum gas (LPG) sensing behavior of strontium ferrite film was investigated at room temperature. The variations in electrical resistance of the film were measured with the exposure of LPG with respect to time as a function of concentration (0.5–5 vol.%) of LPG. The maximum value of sensitivity for these films was found 7 and maximum sensor response was 602.23.