Low-cost preparation of La4Co3O9 perovskite thin films with distinct absorbance ability and ferromagnetic behaviour.

La 4 Co 3 O 9 perovskite thin film was grown on a glass substrate using spray pyrolysis technique at 460 °C. X-ray diffraction (XRD) pattern indicates a high orthorhombic structure in Ruddlesden-Popper phase along (040) orientation. A nanometric scale size varying between 10 and 20 nm of the La 4 Co 3 O 9 films were proved via Transmission Electron Microscopy (TEM). The High-Resolution Transmission Electron Microscopy (HRTEM) specifically displayed the lattice fringe among the (040) and (1 10 0) planes. A direct transition band was revealed in the synthesized La 4 Co 3 O 9 films through transmittance and reflectance spectra, with a band gap of 1.42 eV. Urbach effect as well as a relatively high absorptivity were evidenced. The prepared thin films exhibit a ferromagnetic behaviour. The saturated magnetization (M S) and coercive field (H C) were equal to M S = 4.69810−4 emu/g and an H C = 45.56 Oe, respectively, at room temperature. The revealed ferromagnetic behaviour was due to the non-stoichiometry of La 4 Co 3 O 9 constituents. The present work emphasizes the specificity and suitability of La 4 Co 3 O 9 thin film perovskite for magneto-optical applications. [ABSTRACT FROM AUTHOR]