Growth of Oriented Thick Films of BaFe12O19by Reactive Diffusion

Single crystal growth of BaFe₁₂O₁₉ by the solid state crystal growth method was attempted. Seed crystals of α-Fe₂O₃ were pressed into pellets of BaFe₁₂O₁₉ + 2 wt% BaCO₃ and heat-treated at temperatures between 1150∘C and 1250∘C for up to 100 hours. Instead of single crystal growth taking place on the seed crystal, BaO diffused into the seed crystal and reacted with it to form a polycrystalline reaction layer of BaFe₁₂O₁₉ . The microstructure, chemical composition and structure of the reaction layer were studied using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), x-ray Diffraction (XRD) and micro-Raman scattering and confirmed to be that of BaFe₁₂O₁₉ . XRD showed that the reaction layer shows a strong degree of orientation in the (h00)/(hk0) planes in the sample sintered at 1200∘C . BaFe₁₂O₁₉ layers with a degree of orientation in the (hk0) planes could also be grown by heat-treating an α-Fe₂O₃ seed crystal buried in BaCO₃ powder.