Microstructural, Magnetic and Microwave Properties of Large Area BaFe $_{12}$ O $_{19}$ Thick Films

We have demonstrated the feasibility of thick BaFe₁₂O₁₉ ceramic films fabricated on silicon (100) substrates. We obtained large area (1-in diameter) thick films (100-200 mum) by using a screen printing technique and amorphous SiO₂ or Al₂O₃ buffer layers. To characterize the microstructural, magnetic, and microwave properties of ferrite films, we employed X-ray diffractometry, scanning electron microscopy, energy dispersive X-ray spectroscopy, dc magnetometry, and ferromagnetic resonance (FMR). We placed our emphasis on investigating silicon diffusion in terms of a depth analysis of composition for different buffer layers. We present and discuss FMR measurements for two polycrystalline samples with different buffer layers. We find that a-Al₂O₃ is superior to a-SiO₂ as a buffer layer in achieving a tradeoff between magnetic and mechanical properties.