Hexagonal BaTiO3/Ni0.8Zn0.2Fe2O4 composites with giant dielectric constant and high permeability

Hexagonal BaTiO3/Ni0.8Zn0.2Fe2O4 (BT/NZO) composites were synthesized by solid–state reaction method. Phase composition, microstructure, dielectric and magnetic properties of the composites were investigated. The BT/NZO composites had giant dielectric constants and very high permeabilities simultaneously. According to Cole–Cole plots, the composites showed a polydispersive nature of the Maxwell-Wagner relaxation. The forming mechanism of hexagonal BaTiO3 in the composites was also investigated.

► The BaTiO3 in the composites is not of tetragonal phase but of hexagonal one.
► The composites possess giant dielectric constants and very high permeabilities.
► The dielectric relaxation of the composites has been investigated in detail.