Magnetic field tuning of hybrid modes in a composite microwave resonator with iron borate

Iron borate (FeBO 3 ) belongs to the important class of magnetic materials, so-called weak ferromagnets. The crystallographic structure of such compounds permits relativistic Dzyaloshinsky-Moriya interaction between constituent magnetic ions that lead to canting of the otherwise collinear antiferromagnetic arrangement and appearance of a small net ferromagnetic moment. The weak ferromagnetism and related phenomena attract attention of modern researchers. Among others, the giant magnetoelectric effect in samarium-substituted iron borate has been observed using spectroscopic experiments in the terahertz frequency range [1].