Modulation mechanisms of dodecahedral site vacancy defects on the magnetic and dielectric properties of YIG microwave ferrites

The design and synthesis of high-performance microwave ferrites represent an essential pathway for enhancing the functionality of microwave devices and systems. In this study, Y3−xIn0.4Fe4.6O12.0−1.5x ferrites were synthesized via a solid-state reaction method. Dodecahedral site vacancies were successfully introduced into the YIG ferrite structure through a non-stoichiometric composition, as confirmed by Rietveld refinement of X-ray diffraction (XRD) patterns. The microstructure, magnetic, and dielectric properties of the ferrites were systematically characterized and analyzed using XRD, scanning electron microscopy (SEM), vibrating sample magnetometry (VSM), impedance spectroscopy, and the TE106 mode cavity perturbation technique. A moderate concentration of dodecahedral cation vacancies was found to improve the microstructural morphology and enhance the dielectric constant while maintaining a relatively low ferromagnetic resonance (FMR) linewidth. Specifically, at x = 0.20, the Y2.8In0.4Fe4.6O11.7 sample exhibited a low FMR linewidth, elevated dielectric constant, and stable magnetization. The proposed strategy of introducing dodecahedral site vacancies provides a novel approach for optimizing the performance of ferrite materials and holds significant scientific and practical value for the miniaturization and integration of microwave communication devices.