Integration of nonreciprocal ferrite microwave devices with semiconductor platforms would allow for reduced volume and weight in phased array radar electronics, in addition to enhanced bandwidth and power management. Barium hexaferrite (BaM, BaFe₁₂O₁₉) is ideal for microwave device applications because of its large (17 kOe) uniaxial magnetocrystalline anisotropy, high resistivity and permeability at high frequencies (>40 GHz). Although previous BaM films deposited on 6H-SiC by pulsed laser deposition (PLD) showed high magnetic anisotropy fields (>15,000 Oe) and strong crystal texture mostly with c-axis perpendicular to the films, the microwave losses of these films as determined by ferromagnetic resonance (FMR) peak-to-peak derivative linewidths (DH), were broader than 1000 Oe. The magnetic quality of the films could not be improved by use of a magnesium oxide (MgO) interlayer grown by PLD due to high porosity and less c-axis perpendicular crystal orientation in the BaM film. However, with the introduction of an interwoven layer of MgO and BaM of approximately 16 nm thick at the film-substrate interface, improved BaM films with saturation magnetization (4πMs) of 4.3 kG, coercivity of 389 Oe, and FMR linewidth of 500 Oe, have been achieved. X-ray photoelectron spectroscopy (XPS) surface analysis and depth profiling showed that the interwoven layers effectively prevent the interdiffusion between the BaM film and the SiC substrate, resulting in more stoichiometric Fe/Ba ratios in the films compared to those films deposited without the interwoven layers. In addition, scanning electron microscopy (SEM) and atomic force microscopy (AFM) results suggested that the MgO/BaM interwoven layers promote two-dimensional growth and improve c-axis perpendicular orientation of the BaM films, possibly through relief of the lattice mismatch between the BaM and the SiC. Although the MgO/BaM interwoven layers addressed the interface mixing and lattice mismatch quite well, the resulting BaM film does not meet the device requirement of an FMR linewidth narrower than 150 Oe. By the use of molecular beam epitaxy (MBE) to provide a single crystalline MgO(111) interlayer of approximately 10 nm on 6H-SiC (0001), high quality epitaxial BaM films were deposited by PLD with a perpendicular anisotropy field of 16.6 kOe, a 4πMs of 4.3 kG, a coercivity of 120 Oe and a FMR linewidth at 56 GHz of 220 Oe. The FMR linewidth was reduced to ~96 Oe after a post-deposition heat treatment, which suggested the post-annealed film is of sufficient quality to pursue the microwave device applications. Compared to the films grown on MgO/BaM interwoven layers, X-ray θ-2θ diffraction measurements showed a strong (0, 0, 2n) crystallographic alignment without any existence of random orientation peak, AFM revealed much smoother surface with root-mean-square (rms) roughness of 1.31 ± 0.23 nm, and XPS showed most stoichiometric Fe/Ba ratio of 12 in film without any interdiffusion at the MgO/BaM and MgO/SiC interface. The combination of high quality, thin, MBE-grown MgO interlayer and subsequent thick PLD-grown BaM film has been established to be a simple and successful method to realize effective integration of BaM with SiC for microwave device applications.