Optimization of artificial multifunctional K0.5Na0.5NbO3 - CoFe2O4 ceramics
Résumé
Lead and rare earth-free (1-x)K0.5Na0.5NbO3– (x)CoFe2O4 composites (where x = 0.05, 0.10 and 0.20), consisting of ferroelectric K0.5Na0.5NbO3 (KNN) matrix and ferromagnetic CoFe2O4 (CFO) nano-inclusions, were densified via spark plasma sintering (SPS) to develop multifunctional materials. X-ray diffraction (XRD) confirmed the absence of secondary phases. High resolution scanning electron microscopy (HR-SEM) revealed dense microstructures, with increasing CFO grain size at higher CFO content. Energy dispersive X-ray spectroscopy (EDS) mapping and scattered scanning near-field optical microscopy (s-SNOM) confirmed CFO distribution in KNN matrix. Ferroelectric hysteresis loops demonstrated ferroelectricity in all composites. Dielectric measurements howed relaxation behavior with increasing losses for higher CFO content. Magnetic analysis at room temperature indicated a dominant ferromagnetic behavior, with superparamagnetic and diamagnetic contributions from CFO and KNN, respectively. Our complete full knowledge studies functionalities will be helpful to build ceramics architectures suitable for magneto-electric properties