Novel magnetic–dielectric composite ceramic obtained from Y₃Fe₅O₁₂ and CaTiO₃

Highlights: • The density of composites was improved with addition of CTO. • Dielectric permittivity of the composites presented values above the expected. • The composites presented magnetic permeability higher than YIG after 500 MHz. - Abstract: This work investigates the microstructure and magnetic–dielectric properties of the CaTiO₃ (CTO) and Y₃Fe₅O₁₂ (YIG) composite ceramic. CTO is a paramagnetic ceramic, presents a positive value of Resonant Frequency Temperature Coefficients (τ_f) and has high dielectric permittivity (ε_r) while YIG is ferromagnetic, has low ε_r and negative τ_f values. Therefore, it is expected that the composite from these individual phase shows new properties, or a mix of them derived from each component. X-ray powder diffraction (XRPD), Scanning Electron Microscope (SEM), Raman and ⁵⁷Fe Mössbauer spectroscopy were performed to confirm the phases of the composites. The dielectric and magnetic properties in Radio-Microwave frequencies were studied by impedance spectroscopy using different geometries. It was observed a densification improvement resulting from the insertion of the CTO in composites and a chemical reaction between YIG and CTO phases. This new composite has potential applications in bulk and thick/thin films devices