Epitaxial growth of M-type Ba-hexaferrite films on MgO (111)∥SiC (0001) with low ferromagnetic resonance linewidths

Barium hexaferrite (BaM) films were deposited on 10 nm MgO (111) films on 6H silicon carbide (0001) substrates by pulsed laser deposition from a homogeneous BaFe12O19 target. The MgO layer, deposited by molecular beam epitaxy, alleviated lattice mismatch and interdiffusion between film and substrate. X-ray diffraction showed strong crystallographic alignment while pole figures exhibited reflections consistent with epitaxial growth. After optimized annealing, these BaM films have a perpendicular magnetic anisotropy field of 16 900 Oe, a magnetization (as 4 pi M-s) of 4.4 kG, and a ferromagnetic resonance peak-to-peak derivative linewidth at 53 GHz of 96 Oe, thus demonstrating sufficient properties for microwave device applications. (C) 2007 American Institute of Physics.