Investigation of Ferromagnetic Resonance Shift in Screen-Printed Barium Ferrite/Samarium Cobalt Composites

This paper explores a method for incorporating samarium cobalt (both Sm ₂ Co ₁₇ and SmCo ₄ ) inclusions into screen-printed barium hexaferrite (BaFe ₁₂ O ₁₉ ) films in order to tune the ferromagnetic resonance (FMR). Using an all-low-temperature screen-printing process, >140- $\mu \text{m}$ -thick composite films are fabricated using heterogeneous mixtures of magnetic particles in a polydimethylsiloxane (PDMS) binder. RF characterization is performed using two-port S-parameter measurements on a coplanar waveguide (CPW) with external magnetic bias fields. The films exhibit a self-biased FMR response that ranges from 41 to 53 GHz (12-GHz span) by varying the relative ratio of the hexaferrite and Sm-Co particles. These effects are attributed to the embedded Sm-Co particles providing additional internal field bias acting on the barium ferrite.