Barium hexaferrite films prepared by the sol-gel method for nonreciprocal applications

In this work, hard magnetic barium hexaferrite films are produced by means of the so called sol-gel method. Compared to other fabrication processes, this technique is rather simple and low-cost. Furthermore, the method offers the advantage of requiring a comparably low temperature to sinter the final magnetic film. This low sintering temperature enables integration of these films into LTCC. Due to the self-bias capability of the material, which is caused by magnetocrystalline anisotropy, no means of magnetic biasing needs to be integrated along with the component. The anisotropy of the material can be influenced via doping. So, a large frequency range for potential applications can be covered. Especially for future satellite communications at Q-/V-band, self-biased nonreciprocal components, and therefore hard magnetic ferrites capable of integration, are of interest.