X-ray absorption spectroscopic study of barium ferrite thin films synthesized by sol–gel method

A sol–gel method was used to synthesize the precursor of barium ferrite in which nitrate salts were chosen as the starting materials with ethylene glycol as the solvent. The effect of vacuum suction process in precursor preparation on the structure of resultant thin film specimens was investigated by means of X-ray absorption spectroscopy (XAS). The result shows that vacuum suction during the precursor preparation can enhance the formation of barium ferrite phase with a spinel structure in the annealed thin film. However, non-vacuum treated specimen favored the hematite phase after annealing. A mechanism is proposed to describe the detail of the phase formation.