Dielectric and multiferroic properties of Na0.5Bi0.5TiO3-CoFe2O4 heterostructure composite ceramic

Multiferroic is the future of the next generation memory devices; because of its advantages over the single-phase ferroelectric and ferromagnetic memory systems. In conventional ferroelectric memory system fatigue effect lowers the storage capacity. Other side high magnetic energy is essential for writing the data in ferromagnetic-based memory system. Considering these facets and taking environmental issue in the account we developed lead-free Na0.5Bi0.5TiO3 (NBT)-CoFe2O4 (CFO) multiferroic system via two wet chemical methods. To check the feasibility of the system for device application various physical measurements were carried out. The structural analyses have been done by XRD, FTIR and FESEM which confirm the coexistence of bi-phase in these composites. The dense microstructure was observed for composite sample with highest CFO concentration. In comparison to pure ferrite phase, the composite exhibit low leakage current density, high dielectric constant with low dielectric losses. Interestingly, the CFO affected the phase transition temperature of the NBT as evidenced by the dielectric behaviour as a function of temperature. Also, multiferroic studies were influenced by the content of CFO/NBT phases in composite system. Furthermore, the highest value of ME coupling (similar to 64 mu V/Oe-cm) was observed for the 50CFO/50NBT composite system.