Manipulating resonances and absorptions of terahertz ferrite ceramics

Abstract

Ferrites are widely used in the preparation of basic components that function within the microwave band. Compared with ferromagnetic ferrites, which possess a weak internal anisotropy field so that the working frequency of ferrite ceramics cannot be increased into the terahertz band, antiferromagnetic rare earth orthoferrites undergo strong interactions on the order of 100 T so that terahertz (THz) resonances can be supported. However, the zero or near-zero magnetization and internal dipolar fields complicate the manipulation of the THz responses in antiferromagnets using the traditional magnetic method. In this article, we choose PrFeO3 as a model of rare earth orthoferrites and report a method of cooling and thickening to tune the THz resonances and absorptions. A combination of tuned time- and frequency-domain spectroscopic responses, including variations in amplitude with the time delay, changes in the transmittance, the peak height, the extinction coefficient κ, dissipation factor tanδ, and absorption coefficient α, which varied with frequency, reveal that our approach is effective. In this work, the resonant frequency of ferrites is promoted to the THz band, providing a highly effective approach for exciting and tuning their resonances and absorptions and offering support for the application of ferrite ceramics in the field of terahertz devices.