Fabrication and characterization of Ba3Zn2Fe24O41 (Zn2Z) hexaferrites films on silicon substrates

We report the fabrication and characterization of Ba3Zn2Fe24O41 (Zn2Z) hexaferrite films on silicon substrates using a simple sol-gel drop casting method. A combination of X-ray diffraction (XRD), scanning electron microscope (SEM), grazing incidence wide angle X-ray scattering (GIWAXS) and vibrating sample magnetometer (VSM) was used to characterize the structural and magnetic properties of the films. The XRD results confirmed the formation of the Z-type hexaferrite with some ZnFe2O4 and α-Fe2O3 phases. SEM images showed several micron-size platelet-like hexagonal crystals with nanocrystals grown onto their surfaces. Interestingly, a few regions of the film exhibit self-assembly of the nanocrystals in ordered patterns. GIWAXS measurements indicated that the crystals are not randomly oriented within the film. The magnetic results revealed typical characteristics of a soft magnetic material consistent with the Z-type characteristics. The magnetization did not reach saturation up to the maximum applied field of 6 kOe. The saturation magnetization obtained with the field applied perpendicular to the film plane was found to be lower than that for a parallel geometry.