Radio-frequency magnetron sputter-deposited barium hexaferrite films on Pt-coated Si substrates suitable for microwave applications

Hexagonal barium ferrite films were deposited on Si (1 1 1) substrates by radio-frequency magnetron sputter deposition. The films exhibited strong c-axis perpendicular orientation benefiting from a Pt buffer layer. The results include measurements of crystallographic structure, magnetic domain structure, and magnetic and microwave properties for barium hexaferrite films with different thicknesses of Pt underlayers, revealing ferromagnetic resonance linewidths, ΔH = 400–600 Oe at 40–60 GHz. These results provide a viable pathway to realizing miniaturized microwave devices integrated with semiconductor device platforms.