The Giant Dielectric Constant and High Initial Permeability of BaTiO3-Ni0.5Zn0.5Fe2O4 Composite Ceramics

Abstract

Fully dense lead-free multiferroic composite ceramics (1-x) BaTiO3-x Ni0.5Zn0.5Fe2O4 (x = 0.2, 0.5 0.8) were prepared by conventional oxide ceramic process. The influence of Ni0.5Zn0.5Fe2O4 (NZF) ferrite content on the dielectric constant/loss and ferromagnetic property of the composite ceramics is investigated in detail. With the increase of NZF ferrite content from x = 0.2 to x = 0.5, the dielectric constant of the ceramic samples is decreasing while the dielectric loss increases. A giant dielectric constant (εr = 312,000) with a dielectric loss relaxation is observed in the sample with x = 0.8, which is well consistent with Maxwell-Wagner interfacial polarization model. The magnetic properties of these composite ceramics are also discussed. With the increase of the NZF ferrite content, the saturation magnetization of the composite ceramics is enhanced obviously. A high initial permeability (38.06) and a low static magnetic loss (1.12 × 104 J/m3) are estimated based on the ferromagnetic loops of 0.2BTO-0.8NZF ceramic.