Synthesis of the thin films of multiferroic $\mathrm{Co:BaTiO}_3$ by ion-stimulated deposition

We synthesized thin films of composite multiferroic $\mathrm{Co:BaTiO}_3$ and analyzed their structure and optical and magnetic properties. The films were prepared using ion-stimulated deposition. Ceramic $\mathrm{BaTiO}_3$ and metal cobalt plates were used as targets. The nanocomposite $\mathrm{Co:BaTiO}_3$ films were annealed in air at temperatures from $250$ to $750^\circ$ С. We studied the element composition, morphology, crystal structure, and optical, dielectric and magnetic properties of the films. Just after preparation and after annealing till $500^\circ$ С, the composite films consist of a dielectric matrix and nanoscopic cobalt particles, which is confirmed by optical spectra and magnetic measurements. The increase of the annealing temperature to over $500^\circ$ С leads firstly to the growth of the particle size and then to the oxidation of metal cobalt to oxide. We defined optimum conditions for the ion stimulated deposition and thermal annealing of thin-film multiferroic $\mathrm{Co:BaTiO}_3$.