Low-Loss Composite NiCuZnCo–BaTiO3 With Matched Permeability and Permittivity in High Frequency Range

The magnetic and dielectric properties of the composites Ni_0.35Cu_0.18Zn_0.45Co_0.02Fe_1.95O₄ + x wt% BaTiO₃(x = 0, 5, 10, 15, 20, 25) were investigated. All samples were sintered at 1080 °C for 3 h to obtain approximately equal real permeability and permittivity. X-ray diffraction results indicated that there had no obvious reaction between the NiCuZnCo ferrite and the BaTiO₃ in all samples. BaTiO₃ powder could obviously suppress grain growth of the composites. The sample Ni_0.35Cu_0.18Zn_0.45Co_0.02Fe_1.95O₄ + 15 wt% BaTiO₃ presented a real permeability of ~29 (loss tangent ~0.02) and a real permittivity of ~28.3 (loss tangent ~0.002), respectively, over 3-30 MHz. This composite material had potential prospects in antenna miniaturization at HF band (3-30 MHz).