Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

This paper reports on the first study of chemical, optical, and structural properties of lanthanum ferrite oxynitride thin films deposited by reactive magnetron sputtering. Thin films were deposited in a Ar/O₂/N₂ mixture as reactive plasma, from two elemental La and Fe targets, at room and high temperature (25 and 800°C). Films deposited at room temperature are amorphous and have been flash annealed to crystallize the perovskite. Oxynitride properties were investigated and compared to oxide films deposited in Ar/O₂ gas mixture. All oxide and oxynitride films present an orthorhombic structure. However, nitrogen doping limited to 1-1.5% leads to lattice expansion (4%), bandgap narrowing, a lower electrical resistivity in range [25-350°C] , and modification of Infrared and Raman spectra. Electron Energy Loss Spectroscopy measurements clearly show the presence of two nitrogen sites with an “active” intra-granular nitrogen associated to an enhancement of the physical properties.