Novel magnetic-dielectric composite ceramic obtained from Y3Fe5O12 and CaTiO3

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 (τf) and has high dielectric permittivity (εr) while YIG is ferromagnetic, has low εr and negative τf 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.